Possibilities of fleas and mites

I live near small stripe of forest with squirrels and wild birds. My terrace is slightly elevated but still on the ground floor. I do not use it much during the winter so this year I installed a bird feeder and a squirell feeder.

The setup Is a metal railing at the edge of terrace, followed by some very low and thin bushes then maybe 1 meter of empty wood flooring and a sofa. Squirrel feeder is hanging on the railing securely, making it easy to climb the bushes and use it. Bird feeder is slightly further on a small patch of grass near wooden floor, surrounded by same bushes.

All was great in the winter and spring. Now I have a flock of small squirrels as frequent visitors, but also want to start using the sofa. How many of you had issues with fleas and mites in similar setups? I noticed many of the squirrels do seem itchy quite often, so they definitely have either ticks stuck to them, or fleas, or mites.

I don't want to abandon the whole idea, definitely will still leave the feeder during late autumn, winter and spring, but not so sure what to do now...