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.

Numerous predators kill hornets, including frogs, birds, lizards, bats, spiders, and hedgehogs. Some larger predators, including rats, skunks, and racoons, will occasionally attack a hornet nest in order to eat the larvae inside. These natural predators typically don’t eat enough hornets to make them an effective form of hornet control. 

Birds eat grass seed for one simple reason—it’s delicious! The seeds are rich in nutrients such as carbohydrates, proteins, and fats. Seeds are also high in energy, so humans eat trail mix loaded with seeds and nuts for long-distance activities. Grass seed, when unprotected, is also exceptionally easy to access.

It is possible, though unlikely, that a home insurance policy will help cover the costs of professional bat removal. However, some policies will chip in for guano removal and associated repairs, such as replacing drywall. Take some time to read the fine print of your homeowner’s insurance policy and call your provider to inquire about bat removal, guano removal, and related repairs.