Tree squirrels live in the cavities of trees or in tree nests that they construct of leaves, shredded bark and twigs. Eastern fox squirrels and Eastern gray squirrels plague fruit trees in the eastern U.S. and were later introduced to western states. They feed on nuts, apples, apricots, cherries, nectarines, peaches, pears and other tree fruits.
It is possible to net a single tree the same way you would net it to keep birds out, but squirrels will eventually gnaw through plastic if they can't find food more readily elsewhere. Trim limbs so they're 6 to 8 feet away from buildings that squirrels might use as launching pads. If squirrels are jumping off wires onto your trees, slit 2- to 3-inch sections of plastic pipe lengthwise and put them over the wires. When a squirrel gets on a section of pipe, it will rotate, sending the squirrel tumbling.
Squirrels can jump from tree to tree. You can prevent squirrels from climbing the trunk of an isolated tree by circling it with a 1-foot-wide metal collar placed 6 feet off the ground. Circle it with spring-loaded wire so the trunk can grow. Some "sticky" products are marketed to keep pigeons off certain areas. If the squirrels leap to the top of your metal collar, apply the sticky goo at the top of the collar. When a squirrel lands on the goo, it will drop off.
Cage traps capture squirrels alive. If the squirrels are small, you can trap them with a glue trap marketed for rats. If you trap a live squirrel, you're faced with the problem of getting rid of it.
Choker-type box traps are sold to eliminate tree squirrels. When the squirrel grabs the bait, it gets choked. These are like choker-traps used to trap gophers, except that the gopher has to push the bait while the squirrel pulls it. Traps with body-gripping jaws can be set inside a baited box or metal tunnel that can block larger animals.
Bait traps with anything squirrels like to eat. Tie the doors open for two to three days to get squirrels used to feeding there. After that set the traps and check them twice daily. Ordinary rat traps are not always powerful enough to kill mature squirrels. There are kill traps on the market that are strong enough to dispatch squirrels.
You might feel like simply shooting thieving squirrels, but that's not safe in urban areas, and it is illegal in some places. In some states a hunting license is not needed if squirrels are harming fruit trees or other property.
Poisons and Hot Sauce
It is illegal in many states to poison squirrels. Where poisoning is legal, there may be restrictions on the kind of poison that may be used and how it is used. Contact your state department of fish and wildlife to see what rules may apply in your area. One idea is to rub hot sauce on your fruit. Once a squirrel chomps into hot fruit on a tree it will avoid that fruit in the future. You can wash the hot sauce off later.
The rules governing the shooting and trapping of squirrels varies by state. Contact your state fish and wildlife service to see what rules might apply. Squirrels are often infested with fleas and mites, and they can transmit tularemia and ringworm to humans. Use plastic or rubber gloves when you handle a dead squirrel; place it in a plastic bag, seal it, and discard it in a garbage can.