Mammals are often active at night, and may therefore be strongly affected by artificial light. Artificial light may cause small mammals to limit their activity and to stay in their burrows. Most species of bat shy away from light as well. Very little is known about the impact of light on large mammals.
Interestingly, a lot is known about mouse behaviour in the laboratory, but very little in the field. In contrast, there is quite some knowledge on the impact of light on bats – both on avoidance and attraction. For all mammal species, there is very limited information on long-term effects at the population level.