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 are common throughout the world and occur naturally in North and South America, Europe, Asia and Africa. Their abundance is perhaps supported by the fact that there are well over 250 squirrel species, including types of ground squirrels, tree squirrels, chipmunks, marmots and flying squirrels.Still, most of these small to medium-sized rodents share similar breeding habits.heir abundance is perhaps supported by the fact that there are well over 250 squirrel species, including types of ground squirrels, tree squirrels, chipmunks, marmots and flying squirrels.