The system that circulates blood through the body, consisting of the heart and blood vessels. In all vertebrates and certain invertebrates, the circulatory system is completely contained within a network of vessels. In vertebrates, the lymphatic system is also considered part of the circulatory system.
While a squirrel isnât going to pen the next bestseller or ace a calculus class, the squirrel is smart in his own way. When looking at animal intelligence, humans shouldnât judge animals by human standards.
Adaptation. One adaptation that is extremely beneficial to a squirrel's lifestyle is the anatomy of their back legs. Squirrels are able to rotate their hind feet which allows them to descend down a tree head first.This is helpful for avoiding predation as well as reaching for food and traveling from tree to tree.daptation. One adaptation that is extremely beneficial to a squirrel's lifestyle is the anatomy of their back legs. Squirrels are able to rotate their hind feet which allows them to descend down a tree head first.