If you’ve ever startled a squirrel, you may notice a curious behavior. Oftentimes, the squirrel will stop what it’s doing and lie flat on the ground.
Even when it’s not scared, you may see squirrels lying flat on the ground or on a branch in a tree.
There are several reasons for why squirrels will suddenly lie flat on the ground, a patio railing, or tree branch.
Squirrels Lie Flat to Hide and Survive
While it may seem counter-intuitive to suddenly stop in the presence of a danger, the act of lying flat is a protective mechanism for squirrels.
First, the act of lying flat hides the lighter colored belly of a squirrel. The fur color on the outer side of a squirrel evolved to help the squirrel blend in with its environment.
If you’ve ever seen a squirrel against the bark of a tree, you will see how well the fur blends with tree bark (there are some exceptions where non-native squirrels have been introduced such as the melanistic eastern gray squirrel found in many communities around the United States).
Second, the posture of lying flat on a surface also helps to protect the vital organs of a squirrel should it be attacked. This posture also protects the genitalia of male squirrels from being bitten by other squirrels.
Squirrels Lie Flat to Cool Down
Beyond being a defensive strategy, lying flat has other benefits.
Lying flat on a cool surface helps the squirrel cool down by dissipating body heat. By spreading out the body on a patch of ground that is cooler than the surrounding air, the squirrels allows the superficial blood vessels to be in closer contact with the ground.
Lying flat exposes as much of the squirrel’s body surface to the cooler surface so that heat can be transferred from the squirrel to the ground. This strategy of reducing the squirrel’s heat load is called ‘heat dumping’.
Squirrels will find tree limbs, shaded pavement, and other surfaces that are cooler compared to the surrounding air to press their underbellies against. The fur on the squirrel’s belly is thinner compared to the thicker fur on the outer belly.
Squirrels Lie Flat to Rest
Lying flat in a tree when resting helps prevent the squirrel from falling out of the tree.
The prone posture also provides the sleeping squirrel with some protection from predators by camouflaging itself against the bark of the tree.