Strong rodent poison. For indoor use Put some under your kitchen cabinets and behind the fridge, check after a few days and top up when necessary.

Also try and find how they are entering the place. Block up any gaps around pipes with wire wool and stick a piece of board etc over any gaps in the floor boards under cabinets.

Contains Bromadialone. Wash hands after use. For outside use make sure birds cannot access it, put in a bait box. You can make one out of an empty margarine tub. Cut a hole in the side, put poison in then put the lid back on. Put a stone or something similar on it to stop it moving around.