Mammals metabolize ammonia into a molecule called urea: As you can see, this molecule contains two atoms of nitrogen. Although it requires metabolic energy to build, it also is less toxic than ammonia, and it requires less water to flush from the system.Your urine's main nitrogenous waste product is urea.ammals metabolize ammonia into a molecule called urea: As you can see, this molecule contains two atoms of nitrogen. Although it requires metabolic energy to build, it also is less toxic than ammonia, and it requires less water to flush from the system.
Tree squirrels are squirrels that live in trees and ground squirrels, like chipmunks and prairie dogs, are squirrels that live in the ground. As a general rule, tree squirrels have longer life spans than ground squirrels.1.
Squirrels live on every continent except in Australia and Antarctica, according to the BBC. Tree squirrels typically live in wooded areas, since they prefer to live in trees. Ground squirrels live up to their names. They dig burrows, a system of tunnels underground, to live in. Some squirrels also hibernate in burrows during the winter to keep warm.