How Do Squirrels Find Their Nuts?

Squirrels are famous as hoarders of acorns and other nuts. As the squirrel food pyramid indicates, nuts and other plant-based foods make up the bulk of their diets. Since squirrels are active year round, they need to store up food ahead of time to sustain themselves through the winter. Nuts make a great storage food because they can keep for months on end. Most of a squirrel’s winter nut caches are collected and buried in the ground during the months of September and October.1

Nuts About Nuts

Each year, a single squirrel may bury thousands of nuts.2 That’s a lot of food that will later need to be retrieved! Moreover, squirrels can spread their nut caches across an area larger than two square miles, and it may be up to 9 months before they need to return and dig up these stashes.2 So how do squirrels manage to find all these nuts?

Memory, Smell… or Both?

In fact, squirrels don’t recover all the nuts that they bury. They only need to find enough to survive the winter. Squirrels use a combination of memory and smell to relocate buried nuts.2 They’re able to remember the general whereabouts of their caches, and when they’re close enough to where a nut is buried, they can then sniff out its exact location. Interestingly, squirrels will sometimes dig up some of their nuts only to rebury them somewhere else.2


Squirrels and other animals that store food in many different locations are called scatter hoarders.

The fact that squirrels are able to smell nearby nuts explains why they’re often able to find food buried by other squirrels.2 They can also sniff out some nuts more easily than others. For example, squirrels are able to smell buried walnuts from further away than buried acorns.3

Squirrel burying a nut
Squirrel burying a nut

Related Posts


1 Webster, D., Parnell, J., & Biggs, W. (1985). Mammals of the Carolinas, Virginia, and Maryland. Chapel Hill and London: The University of North Carolina Press.

2 Jacobs, L. & Liman, E. (1991). Grey squirrels remember the locations of buried nuts. The Association for the Study of Animal Behaviour, 41: 103-110. Retrieved from

3 Luft, J., Malinowski, J., Briggs, J., & Smith, C. (1994). Odor as a factor in nut discovery by fox squirrels. Transactions of the Kansas Academy of Science, 97(1-2): 1-3.

Why Do Squirrels Have Fluffy Tails?

One of a squirrel’s most distinctive features is her big, fluffy tail. In fact, about half a squirrel’s length is taken up by her tail.1 Other rodents like mice and rats have tails of similar length but without all the fluff. So does this big tail give squirrels any particular advantage?

It turns out that squirrels use their tails for all sorts of things. Fluffy tails help squirrels communicate with each other, perform arboreal acrobatics, and survive extreme temperatures.

Squirrel-to-Squirrel Communication

Squirrels use their prominent tails to communicate with each other in a form of sign language. There are two main types of tail signals. The first is a small up-and-down undulation, and the second is a larger whipping motion.2 This whipping motion is a squirrel’s way of giving an alarm that a predator is near.3 It’s especially associated with indicating to other squirrels that a land-based predator, as opposed to a hawk or other aerial predator, is approaching.4

A High-Wire Balancing Act

Squirrels are often seen running along precariously thin branches and power lines. So how do they keep their balance? A long tail can help an animal run confidently through the treetops by serving as a counterbalance to the animal’s body weight.5 Think of the way a tightrope walker uses a long pole to stay upright on a wire. If a squirrel running along a narrow branch starts slipping off one side, she can move her tail in the opposite direction to balance herself out.

Squirrel running along a power line.
Squirrel running along a power line.

Of course, sometimes even squirrels take a fall. When that happens, their tails once again come in handy. A squirrel’s tail can act as a parachute to slow her down during a fall and then cushion her when she hits the ground.6

Staying Warm and Keeping Cool

Squirrels are active year round, so they need a way to stay warm in the winter and cool in the summer. Apparently, a big, furry tail is the perfect solution. One of the most common postures a squirrel will adopt is to sit with her tail curled over her head like a fuzzy umbrella. Not only does this tail umbrella protect a squirrel from the rain, but it helps her stay cool by shading her from the sun.6 Unsurprisingly, a squirrel’s furry tail also keeps her – and her babies – warm and cozy in colder weather.6

Related Posts


1 Webster, D., Parnell, J., & Biggs, W. (1985). Mammals of the Carolinas, Virginia, and Maryland. Chapel Hill and London: The University of North Carolina Press.

2 McRae, T. (2012). Predator-specificity of multimodal alarm signals in the eastern gray squirrel (Sciurus carolinensis). Open Access Dissertations, Paper 736. Retrieved from

3 Jayne, K., Lea, S., & Leaver, L. (2015). Behavioral responses of Eastern grey squirrels, Sciurus carolinensis, to cues of risk while foraging. Behavioural Processes, 116: 53-61.

4 McRae, T. & Green, S. (2014). Joint tail and vocal alarm signals of gray squirrels (Sciurus carolinensis). Behavior, 151(10), 1433-1452.

5 Young, J., Russo, G., Fellmann, C., Thatikunta, M., & Chadwell, B. (2015). Tail function during arboreal quadrupedalism in squirrel monkeys (Saimiri boliviensis) and tamarins (Saguinus oedipus). Journal of Experimental Zoology, 9999, 1-11. Retrieved from

6 Haupt, L. (2013). The urban bestiary: encountering the everyday wild. New York, NY: Little, Brown and Company.

Why Are Some Gray Squirrels Black?

Black squirrel picture
This black squirrel is a gray squirrel!

If you have squirrels with gray-colored fur in your neighborhood, you’ve probably correctly identified them as eastern gray squirrels. Eastern gray squirrels are the type of squirrel most commonly found in urban and suburban environments.1 Less widely known is the fact that black “suburban” squirrels are also eastern gray squirrels. So why are these supposedly “gray” squirrels black?

The hair of all mammals, including squirrels and humans, contains a pigment called melanin. Mammals produce two different types of melanin, a light-colored version and a dark-colored version.2 The amount of these light and dark pigments present in a squirrel’s fur is what gives the squirrel its distinctive color.

In normal gray squirrels, both light- and dark-colored melanin is deposited in the hair in layers.2 The result is an overall gray appearance. However, some gray squirrels have a mutation that makes their fur black.2 The hair of these squirrels contains much higher quantities of the darker shade of melanin.

Related Posts


1 Haupt, L. (2013). The urban bestiary: encountering the everyday wild. New York, NY: Little, Brown and Company.

2 McRobie, H., Thomas, A., & Kelly, J. (2009). The genetic basis of melanism in the gray squirrel (Sciurus carolinensis). Journal of Heredity. Retrieved from

Do Squirrels Carry Disease?

Squirrels are not known for causing any specific diseases in humans. However, this may be due to the fact that most people don’t come into direct contact with them. Eastern gray squirrels have been found to carry some types of infectious fungi on their fur, skin, and toenails, including a fungus responsible for causing ringworm.1,2 Some other diseases that have been studied in relation to squirrels are West Nile virus, Lyme disease, and the squirrel parapoxvirus.

West Nile Virus and Squirrels3

Squirrels, specifically fox squirrels, western gray squirrels, and our favorite eastern gray squirrels, have been known to fall ill and even die from West Nile virus. Signs that a squirrel might be infected include foot biting, clumsy movements, turning in circles, shaking, and acting fatigued. Even though West Nile virus is usually transmitted through mosquito bites and doesn’t cause illness in most people,4 it’s still best to avoid contact with any squirrel engaging in the previously described behaviors.

Lyme Disease and Squirrels5

Most eastern gray squirrels carry the bacteria that cause Lyme disease. However, squirrels don’t get sick with Lyme disease themselves nor can they pass it directly to other animals. Lyme disease is only transmitted through tick bites. To protect your health when handling squirrels, first check them for ticks or other parasites.


Living in an area with a lot of eastern gray squirrels can actually decrease your chances of getting Lyme disease! That’s because the majority of ticks pick up the Lyme bacteria from mice, so if more ticks are feeding on squirrels, fewer of them will actually become carriers for this disease.

Parapoxvirus and Squirrels6

Eastern gray squirrels can carry a type of virus called a parapoxvirus. Though this parapoxvirus seems to have little to no effect on the gray squirrels, it’s known to infect and kill red squirrels in the UK. Gray squirrels are indigenous to the eastern part of North America7 and are actually seen as pests in the UK, in part because they’re replacing native red squirrel populations. The squirrel parapoxvirus does not affect humans.

The bottom line is that care should be taken when handling squirrels. Remember, all wild animals can carry bacteria or viruses which can then be transmitted to any people who come into contact with them.

Other Popular Questions


1 Lewis, E., Hoff, G., Bigler, W., & Jefferies, M. (1975). Public health and the urban gray squirrel: mycology. Journal of Wildlife Diseases, 11(4), 502-504. Retrieved from

2 Centers for Disease Control and Prevention. (2015). Diagnosis of ringworm. Retrieved from

3 Padgett, K., Reisen, W., Kahl-Purcell, N., Fang, Y., Cahoon-Young, B., Carney, R., Anderson, N., Zucca, L., Woods, L., Husted, S., & Kramer, V. (2007). West Nile virus infection in tree squirrels (Rodentia: sciuridae) in California, 2004 – 2005. The American Journal of Tropical Medicine and Hygiene, 76(5), 810-813. Retrieved from

4 Centers for Disease Control and Prevention. (2015). West Nile virus. Retrieved from

5 Dobson, A., Cattadori, I., Holt, R., Ostfeld, R., Keesing, F., Krichbaum, K., Rohr, J., Perkins, S., & Hudson, P. (2006). Sacred cows and sympathetic squirrels: the importance of biological diversity to human health. PLOS Medicine. Retrieved from

6 Tompkins, D., Sainsbury, A., Nettleton, P., Buxton, D., & Gurnell, J. (2002). Parapoxvirus causes a deleterious disease in red squirrels associated with UK population declines. Proceedings of the Royal Society B: Biological Sciences, 269(1490), 529-533. Retrieved from

7 Jackson, T. (2006). The illustrated encyclopedia of animals of America. London: Lorenz Books.

When Do Squirrels Have Babies?

Different species of squirrel can give birth at different times of the year. For example, white-tailed antelope squirrels have their babies in the spring while southern flying squirrels produce one litter in spring and another in fall.1 There are dozens of different kinds of squirrels in North America alone,2 so as usual, we’ll focus on the most commonly recognized one, the eastern gray squirrel.

When Is the Eastern Gray Squirrel Breeding Season?

Gray squirrels can have up to two litters every year.1,2,3 They usually mate in January and then again in June.3 You can tell they’re getting ready to breed if you see them performing their “pre-mating ritual”, which involves a female leading one or more males on a merry chase. After becoming pregnant, the female squirrel will carry her babies for about 6 weeks before giving birth.1 Most baby gray squirrels are born in the months of March and July.2,4

Baby gray squirrel
Baby gray squirrel

How Many Babies Do Squirrels Have at a Time?

The number of babies in each squirrel litter is variable. Typically, gray squirrels give birth to 2 – 4 babies at a time, but their litters can contain up to 8 young.2 Birth occurs in the nest where the infants will remain until they’re weaned.

Related Posts


1 Jackson, T. (2006). The illustrated encyclopedia of animals of America. London: Lorenz Books.

2 Reid, F. (2006). A field guide to mammals of North America (4th ed.). New York, NY: Houghton Mifflin Company.

3 Webster, D., Parnell, J., & Biggs, W. (1985). Mammals of the Carolinas, Virginia, and Maryland. Chapel Hill and London: The University of North Carolina Press.

4 Hefner, J. (1971). Age determination of the gray squirrel (Master of science thesis). Retrieved from

Where Do Squirrels Live?

There are 3 broad types of squirrels: tree squirrels, flying squirrels, and ground squirrels.1 As their names suggest, tree squirrels live in trees and ground squirrels live in burrows in the ground (in case you were wondering, flying squirrels also live in trees). Most people are familiar with tree squirrels, particularly eastern gray squirrels, so they’ll be our focus.

Where Do Squirrels Sleep?

Squirrels sleep in nests in trees. Usually, they build their nests in the branches of their chosen  tree, but they sometimes den in tree hollows as well.2 Squirrels construct nests out of twigs and leaves and then line and insulate them with moss or other soft materials.3,4

Fun fact: Squirrel nests are called dreys.

From the ground, squirrel nests look like big balls of leaves up in the trees and are easiest to see in the winter when tree branches are bare. Each squirrel can have multiple nests.4

A squirrel nest!
A squirrel nest!

Do Squirrels Live Alone?

Adult squirrels usually live alone, but in cold weather, they may den with other squirrels.4 Of course, baby squirrels live with their siblings and mother in the same nest until they’re old enough to be independent. If the mom has two litters in one year, she’ll move into a new nest to raise the second litter, abandoning the first.1

Other Popular Questions


1 Webster, D., Parnell, J., & Biggs, W. (1985). Mammals of the Carolinas, Virginia, and Maryland. Chapel Hill and London: The University of North Carolina Press.

2 Jackson, T. (2006). The illustrated encyclopedia of animals of America. London: Lorenz Books.

3 Haupt, L. (2013). The urban bestiary: encountering the everyday wild. New York, NY: Little, Brown and Company.

4 Reid, F. (2006). A field guide to mammals of North America (4th ed.). New York, NY: Houghton Mifflin Company.

What Do Squirrels Eat?

Squirrels spend huge amounts of time each day foraging for food. So what are they looking for? Squirrels eat nuts (especially acorns), seeds, flowers, fruit, buds, fungi, and sometimes even insects and baby birds.1,2 If you’ve ever seen a squirrel going through the trash, then you know they love to eat human food as well!

Of course, squirrels don’t eat the same foods all the time. Their diet depends on what’s available during each season. For example, squirrels eat buds in the spring when plants are developing new leaves and flowers and then fruit in the summer when it appears.2

A Quick Guide to Squirrel Nutrition

If you have a pet squirrel, you may be wondering how much of each type of food to feed your furry friend. Fortunately, a healthy and balanced squirrel diet is extremely easy to achieve. Nuts and seeds make up as much as 95% of the eastern gray squirrel diet.3 In particular, squirrels prefer acorns, hickory nuts, and beech-nuts.1,4 Insects and other food derived from animals make up under 2% of a squirrel’s diet.2

What do squirrels eat image

To prevent your pet squirrel from eating too much or too little, we should also figure out the total amount of food he or she needs every day. Let’s start with the fact that the average squirrel eats about 100 pounds of food each year.2 Some simple math will give us our answer:

What do squirrels eat equation

So, your squirrel will need just over a quarter pound of food every day.

What About Baby Squirrels?

Like other young mammals, baby squirrels drink milk from their mothers. Squirrels nurse their young for about 3 months, which is a long time by rodent standards.5 Every mammal produces its own unique type of milk, and squirrels are no exception. Compared to cow milk, gray squirrel milk has less water and sugar but more protein and fat.6

If you’re raising a baby squirrel, you can make your own squirrel milk using this recipe.

Other Popular Questions:


1 Reid, F. (2006). A field guide to mammals of North America (4th ed.). New York, NY: Houghton Mifflin Company.

2 Webster, D., Parnell, J., & Biggs, W. (1985). Mammals of the Carolinas, Virginia, and Maryland. Chapel Hill and London: The University of North Carolina Press.

3 Chung-MacCoubrey, A., Hagerman, A., & Kirkpatrick, R. (1997). Effects of tannins on digestion and detoxification activity in gray squirrels (Sciurus carolinensis). Physiological Zoology, 70(3), 270-277.

4 Nixon, C., Worley, D., & McClain, M. (1968). Food habits of squirrels in Southeast Ohio. The Journal of Wildlife Management, 32(2), 294-305.

5 Haupt, L. (2013). The urban bestiary: encountering the everyday wild. New York, NY: Little, Brown and Company.

6 Nixon, C., & Harper, W. (1972). Composition of gray squirrel milk. The Ohio Journal of Science72(1), 3-6. Retrieved from