There are several animal repellent spray products that repel squirrels with sticky, bad-tasting or bad-smelling substances. They are to be sprayed, spread or sprinkled on feeders, plants or soil. One product made from red pepper is to be mixed in with the bird seed in the feeder. Another is to be dusted on bulbs prior to planting.
Discourage squirrels from raiding bird feeders by using wild bird seed mixes that feature safflower seeds. Since they do not like these seeds, squirrels tend to ignore feeders filled with them.