I'd quietly explain to them that they are living there rent free - in my opinion the quieter the more serious you'll be taken - and that you're really not asking for MUCH!!! ...and that for all you do for them, the decent thing for them to do is GROW!!....and if they can't do that then maybe they'd be happier in THE ALLEY!! I do this with my dogs when I see rabbits in my garden, but I really don't think they get it, but who knows , maybe peonies would understand, they seem a lot smarter than Boomer and Baxter.
