What can I do to stop squirrels from gnawing on things in my yard?
Squirrels are rodents. Rodents have fast-growing teeth designed to gnaw on hard objects. Gnawing keeps their teeth sharp and wears down their teeth so they don't become too long. When there is a shortage of acorns, other nuts, or tree bark to chew on, squirrels may revert to gnawing on other hard objects such as the siding on your house or your deck or bird feeder. Short of providing dental sharpening and grinding service for the squirrels to keep them placated, it may be difficult to keep them from gnawing on objects you want them to avoid.
You may be able to keep them at bay by covering their favored chewing sites with metal flashing or hardware cloth. This may simply force them to begin gnawing elsewhere, however. Check with your local animal control office or fish and wildlife department about the possibility of livetrapping the squirrels to relocate them. Squirrels gnawing on branch tips in spring is usually a temporary phenomenon. They feed on the expanding buds and lap up the nutrient-rich sap from the wounds they make. Once the tree is fully leafed out, they move on to a different food source.