Set live traps or install a one-way door to evict squirrels, rodents, and other animals from your attic. Once they’re out, seal any entry points to prevent the animals from returning. If you’re dealing with an infestation, call a pro. 

Identifying the specific animal running on your roof at night can be challenging without direct observation. Common nocturnal roof visitors include raccoons, squirrels, opossums, and rats. Raccoons are bigger and can create heavy thumping sounds. Squirrels are agile and may produce rapid scurrying noises. Opossums tend to move stealthily with less noise. Rats can make scratching or gnawing sounds. To determine the culprit, look for signs like footprints, droppings, or damaged areas near the roof. For accurate identification, consult a pest control professional or set up wildlife cameras near potential entry points.

The lifespan of a bird's nest depends on the species. The building process can take from two days to three weeks. Once built, the nesting period for baby birds can last from two to ten weeks before they leave the nest. While most young birds are ready in two to six weeks, some predatory species may need up to two and a half months. Some species nest four to five times per year, so a nest could remain in use for several months. For specific information about a particular nest's longevity, it is best to consult a wildlife professional.

Maintain sealed entry points, use deterrents like spikes or sonic devices, and keep areas clean to discourage nesting.