There are lots of ways to tell if you have mice, or other rodents in your home.
Seeing the rodent: Sometimes you may actually see the rodent in your home, or scurrying across the floor. This would be the most obvious way of telling that you have a problem.
Seeing droppings: Mice and rats leave lots of droppings laying around. They vary in size and shape, so if you have not seen the actual rodent, and have only found the droppings, doing some research could help you determine what you are dealing with.
Entry holes: If you find holes chewed anywhere, it could be a sign that you have rodent activity. Keep in mind that mice really only need about a 1/4″ inch hole, so make sure you look closely, as entry holes can be quite small and hard to locate.
Damaged food containers: Mice can and will easily chew through various types of containers to get to food. If you find a bag of dog food, destroyed candy bars, or crumb trails laying around, you may have a rodent problem. Of course, with the exception of the dog food, these could also be signs that you have teenagers, so make sure you correctly identify the pest.
Nesting sites: Mice and rats cat make nesting sites out of items including clothes, newspapers, boxes, etc.
If you think that you might have mice or rats in your home, take action immediately. They can reproduce as young as 4 weeks old, and do so at an alarming rate. One or two mice can turn into an absolute nightmare in no time!