Roof rats have been documented in the Las Vegas valley since 1990, first identified in the south and central valley with imported palm trees and fruit shipments. They climb palms, fruit trees and block walls to reach roofs and attics. The Southern Nevada Health District's plague and hantavirus tests on trapped rats came back negative.
Key takeaways
- Roof rats have been documented in the Las Vegas valley since 1990, first identified in the south and central valley with imported palm trees and fruit shipments.
- They thrive on palms and cypress, year-round water such as pools and irrigation, and fruit and pet food.
- The Southern Nevada Health District trapped nearly 200 roof rats and a few desert wood rats at over 300 homes in 35 ZIP codes, and plague and hantavirus tests were negative.
- Roof rats are climbers, so palms, fruit trees, block walls and rooflines are their route into attics.
- Trapping without sealing tends to fail, because new rats find the same entry points.
- Sealing roofline, vent and pipe gaps is what keeps rats out once the trapping is done.
Are there roof rats in Las Vegas?
Yes. Roof rats have been documented in the valley since 1990, and were first identified in the south and central valley with imported palm trees and fruit shipments. The Southern Nevada Health District has trapped them across the valley. They are an introduced pest, not a native one, and they are drawn to palms and fruit.
Roof rats are not part of the Mojave's original wildlife. Like the Arizona bark scorpion, they arrived with the landscaping boom. Imported ornamental palms and shipments of fruit carried them in, and the valley's new neighborhoods gave them a place to live.
The Southern Nevada Health District has studied them directly. It trapped nearly 200 roof rats, plus a few desert wood rats, at over 300 homes in 35 ZIP codes. That is a wide spread across the valley, and it is why a roof rat sighting in Summerlin, Henderson or North Las Vegas is not a freak event.
If you want to know how this fits with the valley's other introduced pests, the scorpions in Las Vegas guide tells the parallel story for the bark scorpion.
Do roof rats in Las Vegas carry plague or hantavirus?
The Southern Nevada Health District tested the roof rats it trapped, and the plague and hantavirus tests were negative. That is a sourced result and a reassuring one. It does not make rats harmless, and they still contaminate food and damage wiring, but the specific fear of those two diseases was not borne out in that testing.
Most people who find a rat in the attic think first about disease. The honest, sourced answer is reassuring. The Health District trapped nearly 200 roof rats and a few desert wood rats at over 300 homes in 35 ZIP codes, and plague and hantavirus tests were negative.
That is a result about that set of animals at that time, so it should not be stretched into a promise about every rat in the valley. Rats still leave droppings, chew insulation and wires, and foul stored food. Those are reasons to deal with them promptly, even if the headline diseases were not found.
If you have specific health concerns about droppings or contact with a rat, ask a clinician or the Southern Nevada Health District. This page can speak to the testing result but not to your situation.
How do you tell a roof rat from a house mouse?
A roof rat is much larger than a house mouse, with a long tail, large ears and a slim body, and it is a climber that lives in trees, palms and attics. A house mouse is small with a short, stocky look, and it stays lower. Droppings size and where you hear noise help tell them apart.
Size is the first clue. A mouse is small enough to sit in your palm, while a rat is a different scale of animal. Roof rats tend to have a slim body, a pointed nose and a tail as long as or longer than the body. A house mouse has a small body and a tail that looks proportionate.
Behavior helps too. Roof rats are climbers, and sounds in the attic, along the roofline or in the palm fronds point to them. Mice are more likely to be found at ground level, in cabinets, walls and garages, though both can be in the same house.
Droppings are the third clue. A roof rat's droppings are larger than a mouse's, and mouse droppings look more like small grains. Ask a technician to confirm the species, because the fix depends on it.
| Clue | Roof rat | House mouse |
|---|---|---|
| Size | Larger, slim body | Small body |
| Tail | Long, as long as or longer than the body | Shorter in proportion |
| Where you hear it | Attic, roofline, palm fronds, upper walls | Cabinets, lower walls, garage |
| Droppings | Larger | Small, grain-like |
| Habit | Climbs trees, palms and block walls | Stays near the ground |
Why do palms, fruit trees and block walls lead to the roof?
Roof rats are climbers, and a palm trunk, a fruit tree branch or a block wall is a ladder to the roofline. Roof rats thrive on palms and cypress, on year-round water such as pools and irrigation, and on fruit and pet food. A dense palm crown touching the roof is the most direct route.
Valley yards are full of the features roof rats like. Ornamental palms hold old fronds and boots that make cover. Fruit trees drop food. Pools and drip irrigation provide year-round water in a dry climate. Pet food left outside rounds it out.
Block walls are the highways. A rat can walk the top of a perimeter wall from one property to the next, and when the wall touches a house, a tree, or a shed, it has an easy way up. A palm whose fronds brush the roof or a tree limb that overhangs the eave closes the gap.
The practical point is that rats rarely come out of nowhere. There is almost always a route. Finding it is part of the job, and so is cutting it. Trim palms and branches back from the roof, and a rat has to find another way.
- Palm fronds, skirts and crowns that touch or overhang the roof
- Fruit trees that drop fruit and have branches near the eave
- Perimeter block walls that touch the house, shed or a tree
- Pools, leaking drip lines and pet bowls that provide water and food
- Cypress and other dense evergreens against the house
How do roof rats get into attics and what are the signs?
They use gaps at the roofline: tile-roof edges, vents, soffits, utility and pipe penetrations, and gaps where wires enter. Signs include scratching or running sounds at night, droppings, gnawed wires or fruit, greasy rub marks along routes, and chewed material. Noise overhead after dark is the classic sign.
A roof rat does not need a large hole. It can squeeze through gaps far smaller than most people expect. On a valley house, the usual suspects are the ends of tile roofs where the tile meets the fascia, attic vents with damaged screens, soffit gaps and places where pipes, cables or AC lines pass through the wall.
Evidence tends to show up in layers. You might hear scratching or running overhead after dark. You might find droppings in the attic or on a garage shelf, gnawed fruit under a tree, or chewed wiring. A rat's regular path along a wall or beam often leaves a dark, greasy rub mark.
If you hear it, do not wait. Rats chew wiring, and an attic problem tends to grow. A technician can inspect the roofline, the attic and the trees and walls that give access. The roof rat control page describes how a visit works.
- Scratching, scurrying or thumping overhead at night
- Droppings in the attic, garage or along walls
- Gnawed fruit, pet food or packaging
- Chewed wires, insulation or pipe wrap
- Dark, greasy rub marks along beams and walls
- Pale, shredded nesting material in the attic
Why does trapping without sealing fail?
Trapping removes the rats that are there, but it does nothing about the gaps and routes that let new ones in. If the roofline, the palm and the block-wall route are still open, other rats arrive. Sealing roofline, vent and pipe gaps is what keeps rats out once trapping is done.
A trap works on one animal at a time. A house with an open route is a house with a standing invitation, particularly one with palms, fruit and water close by. Remove ten rats and the eleventh may use the same gap.
That is why a sound plan has two halves. The first is removal: trapping, with checks, until the activity stops. The second is exclusion: sealing roofline gaps, repairing vent screens, closing pipe penetrations and cutting back the tree and palm routes.
Do the exclusion after the trapping, so you do not seal a rat inside. A technician plans the order. You can read more on the rodent exclusion page, and sourced price estimates are in the pest control cost guide.
What can you do about roof rats yourself?
Reduce food, water and access. Pick up fallen fruit, store pet food indoors, fix leaking irrigation, trim palms and branches back from the roof, and keep trash lids on. These steps make a yard less attractive, but they rarely remove rats that are already in the attic.
Start with fruit. If you have citrus or date palms, clear fallen fruit regularly and harvest what you will eat. Next, look at water. A leaking drip line or a pool with a low edge gives rats a drink in the dry months.
Pet food bowls and bird feeders are another attraction. Feed pets indoors or take the bowl in at night, and clean up spilled seed. Close trash cans tightly.
Then look up. Trim palm fronds and tree limbs so they do not touch the roof, and keep at least a gap between branches and the eave. If a block wall touches the house or a tree, note it for a technician.
Does it depend on the neighborhood?
Yes, in how it shows up. Older areas with mature palms and fruit trees may have more routes to the roofline, while newer master-planned areas have long block walls and watered landscaping. Roof rats were documented across 35 ZIP codes, so no part of the valley is off the list.
A 1950s tract in Charleston Heights or a 1960s house in Paradise Palms may have mature palms and old trees that have had decades to reach the roof. A 2000s stucco house in Mountain's Edge or Southern Highlands may have younger plantings but long runs of wall and irrigated beds.
A golf-course edge or a pool-heavy neighborhood supplies the year-round water that roof rats like. A senior community such as Sun City Summerlin may have well-kept landscaping, but a mature palm there is as good a ladder as one anywhere.
Whatever the neighborhood, a technician looks at the same things: the trees, the walls, the roofline and the water.
Frequently asked questions
How did roof rats get to Las Vegas?
They have been documented in the valley since 1990 and were first identified in the south and central valley with imported palm trees and fruit shipments. They thrive on palms and cypress, year-round water and fruit and pet food.
Do Las Vegas roof rats have plague or hantavirus?
The Southern Nevada Health District trapped nearly 200 roof rats and a few desert wood rats at over 300 homes in 35 ZIP codes, and plague and hantavirus tests were negative. That is a testing result, not a promise about every rat.
How can I tell a roof rat from a mouse?
A roof rat is larger, slim, with a long tail, and it climbs; you hear it in the attic and roofline. A mouse is small and stays low, in cabinets and garages. A technician can confirm the species, which affects the fix.
Why do roof rats go for palm trees?
Roof rats thrive on palms and cypress. Palm crowns give them cover and a path to the roof, and fruit, pool water and irrigation nearby supply food and drink. Trimming palms back from the roof removes one of the main routes.
Is trapping enough to get rid of roof rats?
Usually not on its own. Trapping removes rats already in the house, but new ones come in through the same gaps. Sealing roofline, vent and pipe gaps, and cutting tree and wall routes, keeps them out once the trapping is done.
Who do I call about rats in the attic?
A local technician can inspect the attic, the roofline and the trees and walls that give access, and explain the plan. You can call (855) 974-4733; phones are answered 24/7, and the price is confirmed on site.
Sources
This guide is general information for Clark County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.