Aquatic mammals spend their entire life in water. Whales are aquatic. Arborial mammals live in trees an example of this is in monkeys. Most arborial animals are either brachiating, or scansorial. Brachiating mammals swing arm to arm from tree limb to tree limb, whereas scansorial mammals scamper through the branches.
Many mammals hibernate.
Hibernation is a way for mammals to survive through the winter if they cannot migrate. Not all mammals hibernate, but those who do, will spend two to three weeks with their body temperature two to three degrees above freezing, their heart rate greatly slowed, and their breaths per minute down to four or five. Like many other animals in the animal kingdom, we obtain many things from mammals. They are a very important part of our ecosystem and without mammals, we would be missing a very big link. Sadly, a species of mammals becomes extinct approxamately once every couple of weeks.