* Vast Diversity: The category of "small mammals" encompasses a huge range of species, from tiny shrews to larger rodents like squirrels.
* Variety of Nesting Strategies: Not all small mammals build nests in the traditional sense. Some use burrows, hollow logs, rock crevices, or even existing structures like birdhouses.
* Seasonal Differences: Some animals only build nests during breeding seasons.
* Species Specificity: Even within a species, nesting habits can vary based on location, climate, and individual preferences.
Instead of an exact number, here's a better understanding:
* Many small mammals DO build nests: Examples include mice, rats, squirrels, voles, and chipmunks. These nests provide shelter, warmth, and a safe place to raise young.
* Others use alternative shelter: Some small mammals, like moles, rabbits, and some bats, dig burrows for their homes.
* There are exceptions: Some small mammals like hedgehogs and porcupines might not construct nests, but find natural shelter instead.
So, rather than a number, it's accurate to say that a significant portion of small mammals use nests or similar shelters.