Question
We have an elevated deck next to a strip of forested land. In the fall and winter, we are invaded by both squirrels and racoons. A racoon came in our cat door the other evening and ate all the food in their bowls! We don't want to kill them, but do not want them. Advice?

Answer
The best advice I can give, in light of your restrictions,  is to seal off the cat door. Don't waste your money on repellents unless you believe in the placebo effect.  Unfortunately, no one has built a cat door strong enough to keep out a raccoon while still permitting a cat to enter. (I for one don't recommend allowing cats to roam free they are too destructive to the environment).
Would need more information on what the squirrels are doing. Invasion means different things to different people.

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