I’ve had a 5’ black snake take 4 eggs at a time from under a broody, digest them, then come back for more two or three days later. If you’re only getting a few eggs a day, that becomes noticeable. Or it sounds like the OP has more than one snake visiting,
Snakes are hard. They can climb really well, get through some pretty small holes, and might visit any time day or night. When my eggs drop from 9 a day average to maybe 5 a day every few days, I suspect a snake. I have had them swallow golf balls and not be able to get back out through the hole they came in. I’m retired so when I suspect a snake is visiting I drop into the coop a lot during the day to try to catch it. I also gather all eggs and don’t leave any in the coop overnight, except when I have a broody.
I’m not sure I believe a snake swallowing a golf ball or ceramic egg will actually kill it. I’ve read they can regurgitate bones and other indigestible parts of their prey. I read that over the internet so I don’t know how reliable it really is.
When I had that snake eating eggs out from under the broody, I put plastic Easter eggs under her, filled with sand and glued shut. That snake did not touch them. I did not try golf balls.
I have not tried this, but someone posted photos on here of their method to trap snakes. They put a minnow trap with eggs as bait along the trail the snake was suspecting of using.
Another method I have not tried is to take some plastic bird netting and twist/tangle that around the coop, again trying to put it where the snake is traveling. The idea is that the snake gets tangled up in it and can’t get away. As I said, I haven’t tried that.
Good luck with your snakes. I usually don’t bother non-venomous snakes too small to eat eggs or baby chicks, but I do get upset when my chicks or eggs get eaten. As long as they stay away from my eggs and chicks I appreciate the mice and such the snakes can eat.
