how do i keep barnswallows from building nest on my porch?

Question

i've knocked it down twice but they keep coming back

Answer 1

Try a fake owl or snake. They should be available at your local garden shop or nursery. You might hire a cat, also. Birds don't like wind chimes, either.

Answer 2

A strategically placed stuffed animal or aluminum foil well detour them.

Answer 3

Move out of the barn.