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.
A squirrel in the University of Cambridge Botanic Gardens. Tree squirrels are the members of the squirrel family (Sciuridae) most commonly referred to as squirrels. They include over a hundred primarily tree-dwelling species, native to all continents except Antarctica and Australia.