This is known as delayed implantation. Hair or fur is a feature in every mammal, even marine mammals like whales and seals. Then there is the porcupine. These unusually dressed rodents are found around the state. The young are born with soft quills that quickly turn brittle after birth.
Mammals are excellent protectors of their young.
A mother bear with her cubs is not beyond aggressive behavior toward an intruder. Not all mammals are seen most often on the earth or in the water. Bats are the only flying mammal in the world. They are not birds. These insect-eating flyers migrate and hibernate.