Q: What do I need to know about rats if I keep chickens?
*Small rodents with long, sparsely furred tails
*Up to 10 inches long (excluding the tail), and sometimes weighing more than two pounds, although they are seldom more than 19 ounces.
Found throughout the world
Rats will generally only prey on chicks and eggs, but if you have a serious infestation and food is scarce, they can also raid your coop at night and attack your juvenile and adult birds.
Rats kill by biting the head or neck, like those from the weasel family. Like opossums, they will drink the blood of their victims. Parts of your chickens bodies may be eaten, and the corpses may be pulled into burrows or other concealed locations for feeding. Sometimes they are just dragged into a corner.
You may not see any rats unless you have a severe problem. They are shy and come out at night. However, if they are around, you may be able to spot chewing damage on your coop. If your coop has no ingress for them, they will make their own, so keep an eye out for gnawed corners! They are also great burrowers and can enter your coop or run from below.
Protecting Your Flock
To keep your flock safe, first, don't attract these predators to your yard. For instance, you may want to remove your flock's feeders and waterers each night and replace them in the morning until the problem is taken care of. While your chickens won't want to eat or drink at night, rats will! So make sure rats are not attracted to your area by eating seed from wild bird feeders, or cat food left out overnight and the like. In dry areas or during dry periods, they may be attracted to sources of water in your yard, too. Don't leave anything out for them!
In addition, be sure to store your chicken feed in predator proof containers--rodents are more likely to chew through wood than plastic, and more likely to chew through plastic than metal. If they have a food source like your stored feed, they will be difficult to get rid of. Don't give them pplaces to hide, either. Many people choose to use chicken coops with floors that are raised and open beneath so rodents don't have good places to hide and chew in from below.
Don't use chicken wire for your coop or run: chicken wire is not a barrier to predators. Most predators can tear through it like tissue paper, and rats can bite through the thin wire as if their teeth were wire cutters. Some smaller rats will simply squeeze through the holes. Chicken wire should only be used to keep chickens in, not to keep predators out. Instead, use hardware cloth, and be sure to provide a small mesh for best protection (1/2" or 1/4").
If you see gnawing damage on your coop, try stapling hardware cloth around the damaged area so they will not get through. Since rats are burrowers, you may wish to wire the bottom of your run, bury the bottom of your fence, or provide an apron so they cannot enter your chickens' area from below. Since they can climb fences, though, the only way to exclude them from the chicken yard absolutely would be a completely enclosed run: top, bottom and sides.
Rats carry disease, so it will be important to control them if you are having a problem. Even if they aren't preying directly on your chickens, when rodents defecate in your chickens' feed when eating it at night, it is bad news. Your chickens may ingest the feces and that can make your girls ill with salmonella or other things. Even so, poison should be used with real care, if used at all. You don't want your chickens getting into the poison; you don't want that risk for your other pets and family members either! You don't want your cats or dogs getting a hold of a poisoned mouse or rat and getting poisoned second hand, either. You don't want a rat or mouse dying beneath your house or coop, or in a wall, and decomposing (stinkily) there. Avoid attracting them to begin with... and if you do encounter a problem, traps and exclusion are usually the best ideas. Your local DNR or extension office may be able to offer you further advice for this problem.