Pest control will deal with them. Call the council.
We once had rats in the attic of our new house. It was a chaotic time, DS2 had just been born and was in SCBU so DH and I were mainly at the hospital with him while my mum was caring for the other two at our house. So she let the rat man in when he came and told him where the problem was located.
At the same time, DS1, then 8, was having poo issues (too many!) and as he has CF we have to keep a v.close eye on these things. GP asked for a sample which my poor mother had the lovely job of collecting from him.
A couple of days later there was a call from the GP about DS's sample.. they were concerned that there appeared to be animal faecal matter among it! Turns out, mum, struggling to collect the sample, had scooped some out of the toilet bowl as DS did it.. saw "something else" in there..and thought she'd better include it as presumed he'd passed it (!)
I phoned the rat man. Turns out, when he'd opened loft hatch, several droppings had fallen out which he'd "disposed of" done out loo! The "something" was a rat dropping!!
I think that particular health centre thought we were mad for the rest of the time we lived in that area! And God knows what the lab thought..
Sorry. Not really a relevant story is it... [gets books and goes upstairs to revise]