Son got bitten recently by an ant and it was a zinger. Lovely sore foot. To be fair he was poking at the nest with a stick and chances are had he not been near the nest would never have been bitten. He learnt a rather painful lesson anyways
I don't do anything in particular to stop spiders or keep them out nor do I really check for them. I have a garden full of them and a shed the size of small planet which has no end of them living in. My one thing was the storage box outside with the lid on but that also keeps things tidy and dry to boot. So win win for me.