Because trailer homes are usually somewhat raised above the ground, and because of the way they are manufactured, there are several more openings and ways that mice and other rodents can make their way in. There are several different methods to catching and killing rodents, in addition to taking additional precautions to ensure that mice do not continue to come into the trailer home.
Use mice traps. Mice traps are the most affordable method of rodent control. There are two different types--traditional and humane. The traditional "spring" kind, which is a metal bar that springs shut onto the mouse, killing it, once it puts weight onto the lever. The humane trap catch the mouse into a small metal box so it can be released back into the wild. Place these traps in the home, as you most likely don't want other animals getting trapped or stealing the bait.
Use mouse poison. This is another affordable method of rodent control. However, if you have pets, it is important to put it in a place where they cannot get to it. Mouse poison can kill dogs and cats if a large amount is ingested. Place the poison around any openings, holes and dark places in the trailer home. Again, it may not be best to put the poison outside underneath the home, as it may harm other animals.
Hire an exterminator. An professional exterminator can come in and spray for rodents. Many times, this is done quickly and certain chemicals will not harm other pets. This is a good option for when you are not sure where the mice are nesting or where they are coming in. An exterminator can spray the entire trailer home. While this is a costly option, it may be the most cost-effective because you aren't consistently spending money on traps.
Get a cat. If they are allowed in your trailer home, a cat might be a good option. This is the most natural way of pest control, as cats are obvious mousers and love to hunt and kill mice. However, you must realize that this may mean that the cat will bring you dead mice as a trophy, or the cat you do bring into your home may not be the best mouser. It is a good idea to adopt a grown cat from a shelter or owner who knows if they are good hunters. Cats raised on farms are usually good mousers as well.
Patch up holes to prevent mice from coming in. If you have tried all of the previous options, then it is time to do some preventative steps. Go around your trailer home and cover or seal (using caulk or other relevant sealants) any holes or openings that allow mice to get in. This includes doorways, around the furnace or other appliance hook-ups, and any cracks in the floors or walls.