Roof rats were brought over to the United States on some of the first ships to reach the New World, and are commonly found in the state of Florida and along the Gulf Coast as they favor warmer climates by the water. While they are generally found outdoors, they may move indoors in the coldest winter months, to warmer enclaves like roofs and attics.
Identifying Roof Rats
Roof rats are much larger than the common house mouse. Their bodies are sleek and agile, with black, hairless, scaly tails that are longer than their heads and bodies combined. They are 12 – 14 inches long and weigh about 5 – 10 oz., with prominent ears and eyes on their heads. Roof rats have been seen to have three phases of coloring – black back with slate gray belly, gray back with lighter gray belly, and brownish gray with a white or cream colored belly. Expert climbers, you can usually spot them above ground in shrubs, trees, and dense vegetation such as ivy. In buildings, you can find them in attics, walls, false ceilings and cabinets.
Once roof rats mature sexually at 3 to 4 months of age, they breed all year-round, producing 4 – 5 litters a year. In each litter, 5 to 8 pups are born after a gestation period of 21 to 23 days. Peak breeding activity is typically in the spring and fall.
Recognizing an Infestation
There are numerous signs of a roof rat infestation in and around your home. Here are some of the evidence of an infestation:
- Rat droppings around your pets’ feeding areas or around pet food storage areas
- Noises in your attic after sunset
- Remnants of rat nests when dismantling your firewood stack
- Your dog or cat brings home dead rat carcasses
- Evidence of teeth marks on fruits/nuts or hollowed out fruit from the trees in your yard
- Burrows among plants or damaged vegetables
- Spotting rats running along utility lines or on fences after sunset
- Smudge marks from the bodies of rats against beams, rafters, pipes and walls
- Burrows beneath compost pile or beneath garbage cans
- Rat droppings in recycle bins
- Drowned rat in your swimming pool or hot tub
- Signs of digging under your garden tool shed or doghouse
Roof rats cause damage to electrical wires and wooden structures of houses like doors, ledges, corners, and wall material by gnawing and chewing on them. They can also tear up insulation in walls and ceilings with their claws and teeth. As they feed on uncovered foodstuffs and animal feed, they can contaminate these food sources and spread diseases to humans, such as murine typhus, leptospirosis, salmonellosis and ratite fever.
There are several techniques that can help contain the damage of roof rats and to prevent an infestation. Preventative measures need to take into consideration the agility of roof rats as climbers.
- Proper spacing and pruning of fruit trees. Keeping trees apart and away from fences, utility lines, branches of other trees will prevent them from moving along these pathways. Trees should be pruned such that the lower hanging branches do not touch the ground, keeping the ground around the tree clear and visible. Fruits should also be picked regularly and fallen fruit should be removed immediately.
- Use of traps. Traps can be placed around the tree trunk or along fences and other common pathways. When using a trap, be sure to set them only from dusk to dawn to avoid trapping other non-target animals. Leave traps in the same position for at least a week before moving them.
- Use of poisons. Poisons should be placed in a tamper-resistant bait station so that children, pets, livestock or wildlife do not have access to them. These should be placed firmly in a fruit tree.
You can rein in your rat infestation problem with natural methods such as by keeping predators, such as cats and dogs, or even introduce biological control such as snakes. Ultrasonic and electromagnetic devices can also emit sounds that can scare off rats. However, these methods may not be 100% effective.
When in doubt, it’s always best to contact a professional. Fischer is your local expert in controlling and eliminating roof rat infestations and can provide you with hassle-free solutions.
Filed in: Rat Attack!