Sorry for your loss. Without some more info,. it is difficult to even reach the ballpark, e.g., did you find the victims in run or were they in coop/condition when discovered (contorted for example)?/did you perform examination (gross necroscopy will answer many questions when COD seems a mystery)? Have you thoroughly poked, prodded and turned over bedding/nest boxes if any, checked around any hiding places in framing (particularly ceiling/beams/corners, any holes/gaps around/in floor of coop - use caution. What constrictors/poisonous snakes are native to your location? What sort of fencing do you use (if pertinent)? Trees/bushes/shrubs adjacent to/over run?
You could test your egg eating serpent hypothesis by supplying putative pred with some fake eggs in nests (only one potential test) - members who've used this method can clue you all on the specifics - and/or you can use Advanced Search to check threads/posts regarding fake & eggs & snake (for example) - just click search button at the bottom of page after declaring variables.
If someone is home during the day, place a baby monitor in coop/run - the chooks will alert to ground pred and you can intervene (a sharpened hoe will do wonders if it is a snake).
Good luck!
I'm sorry for your loss.
