Jeez...give 'em an inch and they take a mile!
It is a liability. It's disrupting your work. It is plain rude to be leaving roaches on your property. Beyond busting through boundaries. I can't even imagine people would do these things. If someone offered me to come use the pool..I'd thank them but graciously decline.
They are sending you guilt gifts.
You are well within your right to rescend.
Good luck, we are all behind you!
Jules