yes most definitly not a raccoon because you would have had chickens killed. some animals that steal eggs are snakes, possums, rats, and skunks. skunks would obviously leave behind their tell tale odor so unless you smell skunks their not your problem either. possums are weird when it comes to chickens because i have seen a video of possums laying in the chicken nest while theres chickens pecking it and hanging around it. so your main suspects would be possums snakes or rats.
P.S if you want to see the possum video go to youtube and type in opossum in chicken coop and it should be there
hope your problem is resolved!!!