I am going to say you either have an Opossum or a Raccoon on your hands. It is kind of hard to tell exactly with just a dust print. Raccoons front paw tracks will look a lot like a human hand print with a more equidistant spacing between the 4 fingers and a larger gap between the first finger and the thumb and a larger pad impression, where an opossum will have a pretty equidistant spacing between all 5 fingers and a smaller pad impression on their front foot. A raccoons pack paw will look a lot like a human foot where an Opossums back paw will look more like a funky human hand (weird spacing on the "thumb" toe). My experience with raccoons and opossums here....I have caught opossums sneaking into the chicken coop late afternoon until just after dark and they have stuck to only eggs. The chickens and ducks aren't super phased by them, they might act a little different but not drastic difference. Raccoons on the other hand, have went for a chicken every time and will wait an hour or two after it gets dark to come up to the coop. If they didn't catch a chicken, then I would have at least 1 chicken missing feathers. And the chickens are totally freaked and off normal behavior for a couple days after the encounter. Raccoons are tricky, smart, and strong. We just lost our favorite silkie roo to a raccoon a couple weeks ago and I have been trying to catch them since. I started with the have-a-heart live traps and they got out of my FIL's large coyote live trap 4 times (pushed hard enough on the top that the door support fell out of place and they could just squeeze under the door and other times reached through between the wall of the trap and the door and squeezed the door support bar so that it folded back and then pushed their way out), they also got out of my raccoon size live trap 3 times. I have since went to a hand trap....and have caught 5 in my day run! Looking at your pics of the prints (fingers look too spread out and evenly spaced to be a raccoon - far left one looks like either a back paw or a double front with back on top print) with measurements, how they only took eggs, and how your chickens were not too phased....I am thinking opossum. Best way to find out though is to set up a game cam. I hope you catch whatever it is!