House Mice

Unfortunately, we are probably all familiar with this little creature. House mice are gray, about 4" in length when fully grown (not including the tail which is also about the length of the body), and weighs only about one ounce. House mice are also typified as having a long pointed nose, large ears, and small eyes. They are extremely good  jumpers and climbers. Mice can easily jump one foot high and can climb up into areas that people may think are impossible for them to get to. They prefer nesting in areas in your home not frequented much, such as an attic where there is plenty of insulation for them to build their nests, wall voids, and stored items such as clothing or boxes. Mice usually do not venture far from their nesting site (only about 20-30 feet) in search of food and water.

Populations of house mice can reproduce rapidly. Females typically become sexually mature at about one month to one and one half months of age and can produce 30 young or more per year.

Signs of house mice will usually be noticed fairly easily. Droppings are the first clue. They are about 1/4" in length, rod-shaped, and pointed at one end. You also may be unfortunate enough to see the mess they left behind after feeding.

Deer Mice

This is the mouse that causes the hantavirus. Human mortality when contracting the hantavirus is said to be 50 to 60%. Before you become too alarmed, I would like to point out that only about 4% of deer mice actually carry the hantavirus and these mice are more of a pest in outer lying areas, such as areas that may be close to fields. 

Deer mice are also known as the white-footed mouse, because of their white under-belly. The rest of their body is brown to dark brown or even almost black in color. They typically will travel with more of a hopping motion than house mouse and have longer hind legs, larger ears, and eyes. The eyes will appear to somewhat bug out from the head.   

Norway Rats

Norway rats grow to a large size of around 10" in body length with a tail of an additional 7-8". They have small eyes and ears, a blunt nose, and coarse brown hair. They do not have good eyesight, but do have excellent senses of smell, hearing, and taste. Norway rats are very cautious, which can sometimes make them difficult to control.  Females can also produce 40 to 45 young per year.

Rats are nocturnal and travel along established routes to get to their food and water sources. They typically forage for food within 150 feet from their nest. Norway rats are omnivorous, but prefer meats and grain products. Their nests usually consist of burrows in the soil or in crawl spaces. If you find damage to any of the food products listed above, burrows in the soil, and droppings that are approximately 3/4" long with blunt ends, you may have Norway rats.

One huge factor in the elimination of rats is sanitation. Sealing cracks around the structure that are 1/2" or larger will also help to block their access. Make sure to also check for cracks around the threshold on doors.

Exclusion Tips

 1) Check to make sure all cracks are sealed, especially any cracks larger than about 1/4".

 2) In areas where it appears that mice may be gaining access into your house, use steel wool to plug the holes.

 3) Make sure your dryer vent is working properly. Your vent outside is an area where mice love to nest or grab lint blown out from the dryer as nesting material. There is a flap which opens when your dryer is on and closes when it is off. Occasionally they will become clogged with lint or will become bent and not close properly.

 4) Make sure all areas where plumbing pipes enter wall voids are sealed.

 5) Make sure that there is no daylight around your garage door and that it seals to the floor properly. Some concrete floors may have a tendency to settle leaving gaps.


Other Preventative Tips

  1) Keep dog food in sealed "mouse-proof" containers, such as large plastic storage boxes.

  2) Keep grass seed, bird seed, etc. in sealed containers and/or on shelves that can't be accessed by mice climbing or jumping. (Keep in mind, mice are great climbers and jumpers)

 3) Water sources for mice should also be eliminated.

 4) Try to keep stored clothing, cardboard boxes for storage, and paper, in areas where it is not accessible to mice.              

Roof Rats

Roof Rats are somewhat smaller than the Norway rat in size. They can grow to 8" in body length and have a long, thin, and scaly tail of up to and additional ten inches in length. They have large eyes and ears, and a pointed nose. Roof rats are different also from Norway rats in that their brown hair forms a smooth coat, droppings are 1/2" in length and come to a point, and prefer to nest in trees or in attics.