Which rodents you meet in Louisiana, and where
Three species cover almost every call, and each one lives at a different height, which is the fastest way to sort out what you have. Roof rats are the climbers. Vines, fence lines, cables and overhanging limbs all lead to a roof edge, and once inside they nest in attics, soffits and above ceilings, coming down at night to feed. UC IPM puts their output at three to five litters a year with up to eight young each, and a mild winter here lets that continue rather than pausing. Norway rats work the ground. Their burrows are open holes about the width of a golf ball in soil beside foundations, sheds and waste storage, and UC IPM reports four to six litters a year with 20 or more young weaned per female. House mice are the interior species, nesting in wall voids and cabinet backs and living on crumbs and condensation. The distinction decides your inspection. Overhead noise means ladder work and roofline sealing. Holes in wet soil mean burrow control and sealing at grade. Droppings in a drawer mean interior trapping and quarter-inch gaps.
What 61 inches of rain does to rodent movement
Rainfall is the most underrated driver of rodent behavior in Louisiana, and it explains why problems seem to appear suddenly. Norway rats live underground. When the ground saturates, and with roughly 61 inches falling in an average year it saturates often, burrow systems flood and the animals have to relocate. What is dry and close by is usually a building: a raised floor, a shed, a garage, a slab edge, or the interior itself through a gap at grade. That is why so many households first notice activity during or right after a wet stretch. The population did not appear that week. It was living outdoors and the water moved it. Two things follow from that. First, drainage is pest work: standing water, clogged gutters, low spots and constantly damp ground under a structure all make the property more attractive and more likely to push animals inside. Second, the sealing has to be done before the rain rather than in response to it. A building closed to a quarter inch does not care how wet the yard gets.
Standing water, rats and leptospirosis
In a climate this wet, water is where rodent control and health advice meet. Leptospirosis is the illness that connects them. Rats shed the bacteria in urine, it survives in water and damp soil, and people are exposed through contact with contaminated water, particularly through cuts or mucous membranes. CDC surveillance recorded 21 US cases through week 13 of 2026 against 22 in the same stretch of 2025, with separate and much higher counts in Puerto Rico, and rodents appear on the agency's list of carriers. Those national numbers are small, and this is not a reason to be frightened of your yard. It is a reason to take standing water seriously as part of rodent work rather than treating it as a separate landscaping issue. Empty saucers and buckets, clear gutters, fix grading that ponds water against a wall, and keep waste containers on a hard surface that can be rinsed. The same logic applies to cleanup: wet the droppings, wait five minutes, wipe and bag, and never sweep.
Sealing that survives Louisiana weather
A lot of exclusion work fails here for reasons that have nothing to do with rodents, so it is worth knowing what to ask for. Expanding foam is the most common shortcut and the least durable. rodents gnaw it easily, and heat and moisture degrade it. Silicone or acrylic sealant used alone has the same problem: nothing about a bead of caulk stops teeth. Fiberglass window screen over a vent lasts about one determined night. What holds up in Louisiana is metal. Quarter-inch hardware cloth over vents and openings, sheet metal flashing at gaps and roof edges, and steel wool packed into irregular voids and then sealed over. Fasteners should be galvanized or stainless, because in 76 percent humidity ordinary screws rust and the patch loosens. Ask any provider which materials they plan to use at each opening, and ask what the warranty says about failures. The answer tells you a great deal. A crew that talks about hardware cloth, flashing and fastener choice is doing exclusion. A crew that talks about foam is doing a temporary patch.
How to compare two rodent proposals
Once you have two quotes, resist the urge to compare the totals first. Compare the work. Start with the entry-point list. Does the proposal name specific openings with locations and materials, or does it describe service in general terms? Only the first came from a real inspection, and only the first can be checked afterward. Next, the visit count. Trapping takes weeks, so find out how many returns are included and what happens if activity has not stopped by then. A good answer includes a re-inspection rather than an open-ended monthly plan. Third, cleanup. Removing fouled insulation, disinfecting and reinstalling is often quoted separately and is frequently the largest line. Ask whether it is in or out so you are comparing the same job. Fourth, the warranty. How long, what does it cover, does it require a monthly contract to stay valid, and does it survive a sale of the house? Then get everything in writing after an inspection and choose on scope, not on the headline number.