The Difference Between Rats and Mice

Mouse sitting on couch
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Besides the fact that rats and mice look different, they are quite a few other differences between them. It is important to know these differences because your rodent control efforts will be most successful when you understand each of these pests, their behavior, food preferences, etc. What works to control mice will not necessarily work to control rats. Here's why:

Mouse vs. Rat

One of the most important differences in behavior between mice and rats are that mice are curious and rats are cautious:

  • The rat is very cautious and will choose to avoid new things in its path until it has had time to get used to them being there. Because of this, you need to place unset traps in the rat's path before putting set rat traps there.
  • Mice, on the other hand, are very curious and will investigate anything new. So you have to do just the opposite for them: Set the trap and put it right in its path. In fact, if you don't catch anything in the first few days, the trap is probably in the  wrong place and should be moved.

Other differences between mice and rats are:

Mice

Living and Breeding

  • Mice prefer to eat cereal grains and plants, but they will feed on almost anything.
  • A mouse will build its nest in a hidden area near a food source. It will use just about any soft material or finely shredded paper.
  • In 1 year, 1 female mouse can breed up to 10 litters of 5 to 6 young - That's up to 5 dozen baby mice in one year!
  • AND - those 60 offspring can begin to reproduce themselves in as little as 6 weeks.
  • Mice usually live about 9 to 12 months (unless we catch them first!).

Movement

  • Mice can stand up on their hind legs - supported by their tails. They do this to eat, fight, or simply figure out where they are. 
  • Mice are excellent jumpers, swimmers, and climbers - they can even climb up rough, vertical surfaces.
  • They are fast runners. Moving on all four legs, they hold their tail up straight for balance. But if they are frightened - they just run straight out!
  • The mouse is nocturnal - it is most active from dusk til dawn. They don't like bright lights, but will sometimes come out during the day looking for food or if their nest is disturbed. 
  • It can slip through 1/4-inch holes and gaps - much smaller than appears possible.
  • The mouse can jump 13 inches high and run along wires, cables, and ropes.

Other Mouse Facts

  • The House Mouse is considered one of the top 100 "World's Worst" Invaders.
  • Mice are afraid of rats! This is because rats will kill and eat mice. Because of this, rat odor can be a strong deterrent to mice and affect their behavior.
  • Mice, themselves, have a musky odor.
  • They are color blind, but their other senses -- hearing, smell, taste, and touch -- are very keen.
  • Mice can be found indoors and outdoors, in cities and rural areas.
  • Signs of mice presence include: droppings, gnawing and tracks.

Rats

Living and Breeding

  • Rats will eat nearly anything, but they prefer fresh grain and meat.
  • Rats need 1/2 to 1 ounce of fluid each day. If they don't get this in the food they eat, they have to find water. 
  • Unlike mice, which rarely burrow, rats will dig under buildings, along fences, and under plants and debris.
  • A female rat can have 6 litters of up to 12 young per year. These 70+ rats can start to breed when by the time they are 3 months old.
  • Rats breed primarily in the spring.
  • Rats can live up to 1-1/2 years.

Movement

  • Rats can enter a building through a hole as small as 1/2 inch in diameter.
  • They are strong swimmers, so, yes, it's true that rats will live in sewers and can enter buildings through broken drains or toilets.
  • A rat will climb to get to food, water, or shelter.
  • They will follow regular routines and paths each day. If new objects are set in its path, it will do whatever it can to avoid it.
  • Rats usually stay within 300 feet of their nest or burrow.

Rat Facts

  • Signs of rat presence are droppings, gnawing, tracks, runways and burrows.
  • Like mice, rats are nocturnal, have very poor eyesight, and have very strong senses of small, taste and hearing.
  • Compared to mice, rats are much larger, have coarser fur, and have proportionately larger heads and feet.
  • The most common rat species in the U.S. are the Norway rat and the roof rat. These two do not get along, and will fight each other to the death. The Norway rat usually wins.
  • But, because the Norway rat tends to live in lower floors of buildings and roof rats in the upper floors, they can both infest the same building at one time.