Ridding your house of mice may be one of the most difficult things a homeowner can encounter. After the initial shock and despair, however, there are steps that may be taken to remedy the problem.
Your home dining life may have to be forever altered. Pristine habits must be adopted. You don't want to leave a trail for mice that ends at one of your comfort zones (i.e., bed, sofa). Food should be consumed neatly in a designated space, like the kitchen.
Your food storage practices may have to change, too. Remove all food sources from a mouse's reach. If snacks, cereals, fruits and the like are typically stored on top of the fridge or on the worktop, relocate them in the refrigerator. It's the only place foods are truly safe from rodents.
Seal off all entryways. Attach a door sweep to all of the doors that lead outside. Locate all holes throughout the flat or house -- in the floorboards and skirting boards, in the walls, and around the piping. Cover the larger holes with sheet metal, cutting pieces down according to the size of the hole, and affix the sheet metal using a staple gun. For smaller holes (remember, a mouse only needs a hole the size of a pencil rubber to squeeze through), apply the silicone caulk generously.
Deter mice from returning. Fill one spray bottle with 30 ml (1/8 cup) of either peppermint or lavender oil (depending on your preference; mice don't care for either) and water to dilute it. Go around the house spraying linens, furniture, rugs and any other items or areas you wish to deter mice from frequenting those areas.
Fill the other spray bottle with a 80 ml (1/3 cup) of either peppermint or lavender soap (again, choose based on your preference) and water to dilute it. Keep this mixture in the kitchen as your pet cleaner. Use it on worktops, appliances, floors and anywhere else that might be appropriate.
Now that you've sealed off all the entryways, set traps (old wooden snap traps are said to work best) in corners around the house, using peanut butter to bait the remaining mice. When the mouse is caught and killed, discard.
If the refrigerator remedy sounds extreme to you, an alternative would be to ensure that all foods not stored in the fridge are put away in durable plastic or metal containers inside cabinets that clearly seal shut. Canned goods are likely safe outside the fridge. Before filling holes, you might spray some of the peppermint or lavender mixture into them for extra measure. Continual spraying with the fragrance mixtures will be required. Soaps and oils may be found online, and often in local chemist's. Allegedly, mice abhor cayenne pepper as well. Be sure to do a thorough search for droppings throughout the house, cleaning up any and all that you see (using disinfectant before handling them with gloves and paper towels). The presence or absence of droppings should help you to monitor the activity of the mice throughout this process. Before discarding mice corpses, spray them with antibacterial disinfectant. Cats, though not sure-fire remedies for this problem, may provide some extra security.
The oil mixture, if not properly diluted, can stain. Proceed cautiously with the snap traps. If you have pets, the snap traps may prove dangerous. Do not use them. Seek alternatives such as humane traps.