Rodent infestations can be very difficult to get rid of, in general mice are less difficult than rats because they travel shorter distances. Before you call an exterminator, there are a few things you can do.
1 remove any available food sources, look around what are they eating? seeds, nuts, trash? chuck it. If you are having trouble finding what they are eating look for poop small, black, skinny footballs.
2 water source ditto
3 If you do not have pets, particularly dogs, get some rodent bait from your local hardware store, always follow the pkg instructions. For mice I like the bags because you can tell if they have been eating it. If you go this route MAKE SURE YOU REMOVE ANY WATER SOURCE the poison makes them very thirsty and you will find lots of dead icky mice near the water source, no water they go in search of it and die elsewhere.
4 Get an outdoor cat
Go pro or not this is going to take a while sorry
FYI the poisons available to you are, in most cases, the same stuff the pros use
Former pest tech