Mice and Rodent Prevention MN
Mice and Rat Biology: Roof Rat (Rattus rattus) is also known as the Black Rat, Ship Rat, or House Rat. It is very common in the more southern states. Adults average 7-8 inches long with an additional 8 inch tail, and weigh between 6-10 ounces. Males are usually larger. They breed year-round, and have up to five litters per year. A female can become pregnant within 48 hours after giving birth. The young grow quickly, and are sexually mature within three months. It’s rare for rats to live more than one year in the wild, though
lab pet rats can live up the three years.
* Characteristics of Rodents |
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Characteristic | Norway Rat | Roof Rat | House Mouse | |||
General Appearance | Large, robust | Sleek, graceful | Small, Slender | |||
Adult size weight(oz/g)length(nose to tip of tail)head and body(mm) tail(mm) |
7-18oz/200-500g7-9.5in/18-25cm6-8 in/15-21cm | 5-9oz/150-250g6-8 in/16-20cm7-10in/19-25cm | 0.4-1 oz/12-30 g2-3.5 in/6-9cm3-4in/7-10cm | |||
Snout | Blunt | Pointed | Pointed | |||
Ears | Small, covered with short hairs; do not reach eyes | Large, nearly naked; can be pulled over eyes | Large, some hair | |||
Eyes | Small | Large, prominent | Small | |||
Tail | Dark above, pale beneath | Uniformly dark | Uniformly dark | |||
Fur | Brown with scattered black; abdomen -gray to yellow-white; shaggy | Gray to black ; abdomen, gray, or black; smooth | Light brown, light gray; smooth | |||
Droppings | Capsule shaped, 2cm/3/4-1 inch | Spindle shaped, 1 cm/0.5 inch | Rod shaped, 3-6 mm/0.5 inch | |||
Senses sight smell, taste, touch, hearing |
Poor, color blind Excellent |
Poor, color blind Excellent |
Poor, color blind Excellent |
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Food | Omnivorous(22-30grams/day) 0.8-1 oz. |
Omnivorous, especially fruits, nuts, grains, and vegetable (15-30 grams/day) 0.5-1.0 oz/day |
Omnivorous, prefers cereal grains(3 grams/day) 0.1 oz. day | |||
Water | 15-30 ml/day | 15-30 ml/day | 3-9 ml/day; can subsist without water | |||
Feeding habits | Shy(new object reaction);steady eater | Shy(new object reaction);steady eater | Inquisitive, nibbler | |||
Climbing | Readily climbs; limited agility | Very agile, active climber | Good climber | |||
Nests | Usually burrows | Walls, attics, vines, trees; sometimes burrows | Within structures, stored food; burrows | |||
Swimming | Excellent swimmer | Can swim | Can Swim | |||
Home range radius | 30-50 m/98-164 ft. | 30-50 m/98-164 ft. | 3-10m/10-33 ft. | |||
Age at mating(months) | 2-3 | 2-3 | 2-3 | |||
Breeding season | Spring and fall peaks | Spring and fall peaks | Year long | |||
Gestation period(days) | 22 | 22 | 19 | |||
Young per litter | 8-12 | 4-8 | 4-7 | |||
Litters per year | 4-7 | 4-6 | 8 | |||
Young weaned/female/year | 20 | 20 | 30-35 | |||
Length of life | 1 year | 1 year | 1 year |
Norway Rat (Rattus norvegicus) Is also known as the Brown Rat. These rats are larger than Roof Rats, with a more robust body, slightly longer, but a bit shorter tail. They can weigh up to a pound. They are more common in northern parts of the country.
House Mouse (Mus musculus) is a common rodent pest inside people’s homes. They are usually around three inches long and weigh less than an ounce. They’re quite a bit smaller than rats. They can have up to a dozen litters per year, and up to a dozen baby mice per litter. That’s gross! Average litter size is closer to six. They rarely live longer than a year in the wild.
Diseases Mice and Rats Carry: Everyone knows about the now-rare Bubonic plague, or “Black Death” of the middle ages, but there are over 30 different types of disease are associated with rats and their droppings. They include Rat-bite fever (Streptobacillus moniliformis bacteria), which is transferred from the bite of a rat, the Rickettsia virus, which is similar to chicken pox, Hantavirus, which can cause febrile illness in humans and sometimes kidney, blood, or respiratory ailments, Eosinophilic Meningitis – an infection of the brain, and caused by rat lung worm. The droppings of rats can cause Leptospirosis or Salmonellosis, and rats and mice also bring parasites into the home.
How Do I Get Rid of Mice and Rats? First of all, do not use poison. Poison will never kill all the rodents, and it’s only a temporary attempt at a solution – once you kill a few rodents, new ones will just come and take their place. They reproduce very quickly, and space or food supplies will dictate populations. Plus, the use of poisons will frequently mean dead and smelly rats in the attic or walls. The only surefire way to get rid of a rat or mouse problem is to find out how they are getting into the building – seal off all of those areas, up to 1/4 inch wide, with steel, and this will keep them out. Once you prevent ingress/egress, you can trap and remove all the rats for a permanent solution. It’s much easier said than done. Even experienced pros can miss the dozens of tiny spots that a home might have that will allow rat or mouse entry. Then trapping is another art unto itself. You can’t just slap a couple of traps near the attic hatch, they must be placed, dozens of them, strategically on the rat or mouse runways in the attic, on pipes, etc.
Once mice or rodents become a problem they can be extremely hard to get rid of. If in a home for a good period of time, a large amount of mice may be living in your attic, foundation or walls without home owners being aware of their presents or damage that is being done. Also, as said earlier they can live off almost nothing! Not only will A Minnesota Animal Control eliminate your rodent problem in your home, they will also ensure they will not come back through proper sealing and guarding of entry points.