What do I need to know about opossums if I keep chickens?
*Medium sized, omnivorous marsupial with an appearance similar to a large rat. They are grey to silver with many sharp teeth, and their long, hairless tails are semi-prehensile.
*Up to 37 inches long (not including tail), and weighing up to 14 pounds
Found mostly in the eastern parts North America, as well as in some introduced areas in the west, especially on the coast.
An opossum that gets into your coop or run will target eggs and young chicks, but they are certainly known to kill adult chickens as well. Small bantams are especially at risk. When they kill adult chickens, they will take one or more, and leave remains quite similar to what a raccoon leaves: the body or bodies will usually be left where they were killed, rather than carried away. The birds will usually be killed by bites to the neck, and the opossums often just eat the contents of your birds' crops and occasionally some of the chest. Sometimes they will just drink the blood--ugh!--little vampires. In any case, they don't normally consume the whole bird.
Opossums are not as wily as are raccoons, and although they can climb fences and dig beneath them, opossums are not as adept at opening locks or latches. However, like raccoons, they can reach their hands through wire mesh that is too small for their whole bodies to fit. In that last case, they will pull out parts of your birds if that is all they can reach. They can also fit through very small openings for their body size.
Protecting Your Flock
First, don't attract opossums or other predators to your yard. For instance, don't leave cat food out overnight, and make sure they will not be attracted to food in wild bird feeders or any seed beneath the feeders. In dry areas or during dry periods, opossums may be attracted to sources of water in your yard, too. Don't leave anything out for them!
Opossums are unlikely to be carriers of rabies because their immune systems are quite strong. Nonetheless, it is still possible, so use caution. They respond to threats by hissing and growling with bared teeth, and they have a vicious bite. Stronger threats that cause extreme fear will sometimes trigger an involuntary reaction of feigning death or "playing possum." When this occurs, not only will an opossum lay motionless with mouth and eyes open, tongue lolling out, but it will also exude a noxious, putrid-smelling, green substance from its anus so that it even smells dead. Anecdotally, in our area, opossums seem to emerge earlier in the evening than other nocturnal predators, and they retire later in the morning.
To keep your flock safe, make sure any wire mesh on your coop is securely attached, because like other small mammals, they will try to pry it off or bend it enough that they can squeeze through. Don't use chicken wire: chicken wire is not a barrier to predators. Opossums and other predators can tear right through it like tissue paper. (Chicken wire should only be used to keep chickens in, not to keep predators out.) Ideally, use hardware cloth with a fine mesh that opossums can't reach through (use 1/2" or 1/4").