Fred and John, I have one machine shed that has no skylights or windows that does have sparrows and robins.

But, there are light gaps around doors. Under doors, 1-3''s They can fly in and out.

Around perimeter base/splash boards.

Thats why I bought a .22 caliber smooth bore rifle, single shot.

Just fun shooting, .22 bird shot.

Do get a small work out:>)

Dang things make you walk back and forth in shed , till they find an exit I missed covering ,or they wear me out flying around.

15'/25' is about the limit to .22 birdshot for me. maybe more, but not much.