Mice

Get a cat! or even encourage someone else's cat to visit you regularly.

What's wrong with mice? Rats are a bigger problem.

If you have an infestation of mice, cayenne pepper isn't going to do anything. As Becasse has said, get a cat, or else get proper traps and poison. If you do nothing but put out pepper, you're going to have major problems.

Once you have dealt with them, you now need to find and deal with the cause of the infestation, and locate where they are entering your property.

If you don't, the mice will come back again, and again, and again, forever.

Rodenticide from Brico.

Put balls of aluminium foil where they generally hide. They don't like aluminium foil.
Don't kill them; it won't solve the problem and it's cruel. If you catch one let it out in the garden. Field mice are a protected species in Europe.
Find the hole and close it.