I'm going to give you a really great "kill" for vermin. All vermin love sugar and if you mix a decent amount of it with hardwall (powder like cement they use for plastering) then put a good tablespoon of this mixture into little paper parcels and leave them along a mouse or rat run, you'll kill the lot and not only that but once they take it their saliva glands turn the hardwall rock solid and kills them almost instantly. This really works and the vermin don't get far, so you can pick them up and dispose of them. Any builder working near you would be sure to have a burst bag of this stuff, or even a hardware merchants. It's a No 1 deliverer of results, guaranteed.