My geese have a cute little house. It looks like a giant doghouse. It’s 6 x 4 for two geese and the edges of the roof are low enough for them to reach so they’ve been chewing on the edges of the shingles. I’m not worried about how it looks as far as roof edge damage - I’m worried about will it hurt the geese if they ingest any of the bits of shingles - they’re standard roofing shingles like I guess you call it asphalt.? It’s like gritty little rocks and stuff. andi guess tar that holds it together? I tried to ask google about birds eating your roof but they only had links about how to protect your roof from bird damage but nothing about the possibility of the roof damaging your birds???