I've had snakes eat gold balls out of nests with no eggs in them, generally at night when they were cold. I've had snakes eat real eggs and leave the golf balls during the day. I've had a snake eat real eggs out from under a broody hen. That one was creepy. I've had a snake eat a baby chick.
My experience is that a snake can come any time, day or night, though they seem to prefer nights. Often when they ate golf balls they could not get back out of the coop through the same hole they entered. That enabled me to find out where the hole was so I could plug it. And I retrieved those golf balls using an ax.
I don't bother non-poisonous snakes unless they are in the coop eating eggs or chicks. I like for them to eat mice. If I find a non-poisonous snake in the coop and can physically catch it (I keep a pillow case and snake catching stick handy) I relocate it to a friend's place several miles away. She wants non-venomous snakes in the hope they'll eat venomous snakes and thus protect her dogs.
I don't know if a snake will regurgitate ceramic eggs or golf balls or not. Some sources say they will, some say they won't. I'm not willing to take the chance that it will suffer so I take the fake eggs back using an ax.
My experiences with snakes is that they take however many eggs they can, depending on size, go away for two or three days to digest them, then come back for more. A five foot long black rat snake took no more than four real eggs at a time, then came back a few days later for more. Those were the eggs under the broody hen.
I don't know for sure it is a snake. Hopefully my experience will help you decide that. These things are not always easy. Maybe a hen is taking them away. Maybe a dog is playing with them. Sometimes it is hard to know for sure.
Good luck!
