Environmental Health Program
Fax407-228-1467 or 407-228-1468
1001 Executive Center Drive, Suite 200
Orlando, FL 32803
Our office provides educational materials and recommends control measures to homeowners who have rodent infestations in their homes and on their property.
The most common rodent pests around Florida homes are:
- House Mouse
- Roof Rat
- Sewer Rat
Rats and mice carry some very serious diseases including:
- Rat Bite Fever
The most important signs of rodent infestation are:
- Gnawing marks on wood, plastic, metal, pipes, and foodstuffs
- Droppings and urine stains in feeding areas
- Dark grease stains from the rat's fur on pipes wires, shelves, and around entrance holes where rats run
- Tail and footprint marks in dust debris; and nesting sites.
Rodent Control Methods
odent Control Methods To control rodents around your home:
- Make sure doors & windows fit tightly and are screened.
- Close other holes through walls with heavy gauge steel wool, galvanized metal, or steel mesh or hardware cloth.
- Tightly seal openings around pipes & wires where they can get into your home.
- Cut grass, brush, and thick bushes within 100 feet of your home.
- Get rid of trash, abandoned vehicles, discarded appliances & junk.
- Store lumber & firewood in neat stacks at least 12 inches off the ground and as far from the house as possible.
- Keep garbage in tightly covered metal or heavy plastic containers.
- Store pet foods and grains in galvanized trash cans with tight fitting lids.
- Don't leave food for pets out overnight - feed only what they will eat within a few minutes.
- Use baits & poisons carefully and only after all other control methods have been used.
- Consult a licensed exterminator for assistance.
- Spring loaded traps and bait stations can be used if properly baited and placed (check daily).
- Spread mothballs around to deter rodents.
- Promptly dispose of dead rodents.
- Additional information on rodent control is available at the Florida Health Rodent web page.
- Remember, for survival, rodents need: food, water, shelter and warmth. Don't provide it!
Rodents are characterized by two continuously growing teeth in the upper and lower jaws which must be kept short by gnawing. The most common rodents found in Florida are house mouse, roof rats and sewer rats.
The House Mouse is shorter, about half the size of a typical rat and has more delicate features. They have soft gray or brown fur and a white under belly and are known for their dark whiskers. Their average body length is about 3-4 inches. Their tails are thin and scaly and run about the length of their bodies between 3-4 inches.
Mice nests are made from fine shredded paper or other fibrous material, are often found in sheltered locations. House mice have a characteristic musky odor that identifies their presence. Mice are occasionally seen during daylight hours.
Mice have offspring of 4-7 babies once a month. Their babies are born without fur, totally pink.
The House Mouse usually feeds on cereal grains, but will typically eat anything. They eat often, nibbling bits of food. They are excellent climbers and can run up any rough vertical surface. Look for droppings, fresh gnawing and tracks indicate areas where mice are active.
- A fully grown rat can weigh as much as a pound.
- Newly born rats can be size of an adult mouse.
- They have thick long tails.
- Their ears are smaller in proportion to their heads.
- They have more blunt features than mice.
- Do not multiply as fast as mice.
- Carry diseases like bubonic plague and typhus which can become epidemic and deadly to humans.
- Their normal life span ranges from 2-5 years.
- Dig deep or long burrows to nest.
- Tend to be more aggressive and will attack.
- Will venture further from their nests to find food.
- Capable of learning and adapting to environments.
- Leave oily stains on walls and openings where they live.
- Their droppings are large and can be up to a 1/2 inch in diameter.
Roof Rats (Fruit Rats)
A typical roof rat is between 13 to 18 inches long from nose to tail. It is commonly known as the black rat, but is often dark brown in color. Unlike other rats, their tails are longer than the length of their bodies and they have large ears.
Roof rats will nest in trees, woodpiles, garbage and plants, but they generally like inside high places, like attics. They sometimes co-exist with sewer rats, though they like to be up high. They are good climbers and only need a hole the size of a quarter to gain entry.
Roof Rats can have up to 8 litters per year each bearing 6-8 rats. They become sexually active 2-3 months after birth.
Roof Rats are most active one hour after sunset and one hour before dawn. They primarily consume fruits and nuts, although they will eat anything. They tend to hoard food for consuming later. They are known for hollowing out citrus fruit in trees or on the ground.
Norway Rats (Sewer Rats)
As an adult the Norway Rat can weigh between 12-16 oz. with a body length of 6-8 inches long. The nose is blunt with small ears, and small eyes. The fur is shaggy and coarse with variation in colors. The tail is shorter than the head and body combined, and scaly.
Norway rats live in close association with people. They burrow to make nests under buildings and other structures, beneath concrete slabs, along stream banks, around ponds, in garbage dumps, and at other locations where suitable food, water, and shelter are present.
In urban or suburban areas they live in and around residences, in cellars, warehouses, stores, slaughterhouses, docks, and in sewers. Although they can climb, Norway rats tend to inhabit the lower floors of multi-story buildings.
Norway rats are primarily nocturnal. They usually become active about dusk, when they begin to seek food and water. Some individuals may be active during daylight hours when the rat population is high, when disturbed (weather change, construction, etc.) or when their food source is threatened.