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.
When looking at animal intelligence, humans shouldnât judge animals by human standards. The best way to judge animal intelligence is how well they adapt and make use of the world around them. Squirrels are experts at adapting, capable of living almost anywhere, so much so that in some areas they are viewed as pests.