Rats in the Attic | Signs and What to Do Tonight

It usually starts the same way. You’re lying in bed and hear something moving above the ceiling: a quick scurry, a scratch, maybe a thump. In Mission Viejo, where tile roofs, mature trees and palms are everywhere, rats in the attic are a common problem. Here’s how to tell what you’re hearing and what to do about it.

Signs of Rats in the Attic

• Noises at night. Scratching, scurrying or light thumping, often loudest just after sunset and again before dawn.
• Droppings. Dark pellets about half an inch long with pointed ends, along rafters, on insulation or near the attic hatch.
• Flattened or tunneled insulation. Rats make paths through it as they travel the same routes every night.
• Dark rub marks. Greasy smudges along beams, pipes and the edges of holes.
• Chewed wiring or ducts. Gnaw marks on cable jackets, flex ducts or stored boxes.
• A sharp, musky smell. Strongest in a closed attic, sometimes noticeable in the room below.
• Rats on the roof or power lines at dusk. If you see them outside, they’re likely getting inside.

Is It Rats or Something Else?

Not every noise in the ceiling is a rat. Timing and sound are the best clues:

If the noise follows the rat pattern and you’ve found droppings, it’s very likely rats. An inspection confirms it.

What to Do Tonight

1. Close the attic hatch or pull-down ladder so nothing wanders into the living space.
2. Put food away. Seal pantry items, and bring pet food and water bowls inside for the night.
3. Keep pets and kids out of the garage and attic access areas.
4. Take notes. Write down when you hear the noise and which room it’s above. It helps the inspection go faster.
5. Look, don’t touch. If you check the attic, use a flashlight from the hatch, and don’t handle droppings or nesting without gloves and a mask.
6. Book an inspection. The sooner the entry points are found, the smaller the job tends to be.

What Not to Do

• Don’t seal the holes yet. If rats are inside when you close the gap, they’ll chew a new way out, sometimes into your living space, or die in the walls.
• Don’t put out poison. Most anticoagulant baits are restricted in California, and a poisoned rat often dies inside a wall or ceiling, where the smell can last for weeks. See Is Rat Poison Legal in California?
• Don’t rely on ultrasonic plug-ins. University of California pest experts don’t consider them effective.
• Don’t sweep or vacuum droppings dry. It can stir germs into the air. Wet them with disinfectant first.
• Don’t wait it out. Rats rarely leave on their own once they’ve found shelter, food and water.

How Rats Get Into the Attic

Roof rats are climbers. In Mission Viejo, they typically reach the roof by:

• Tree limbs and palm fronds that touch or hang over the roof
• Utility lines running to the house
• Fences, vines and trellises along the walls

Once they’re on the roof, these are the usual ways in:

• Open tile ends where bird stops are missing or broken
• Torn or rusted attic and gable vent screens
• Gaps at the eaves and fascia
• Openings where a lower roof meets a second-story wall
• Gaps around pipes, AC lines and roof vents

A gap about half an inch wide is enough for a roof rat. Our Rodent Exclusion page covers how each one gets sealed.

What Happens After You Call

1. Inspection. We check the roofline, attic, vents and yard, and show you the activity and entry points we find.
2. Trapping. Traps go along the runways rats use in the attic, out of reach of kids and pets, and get checked on return visits.
3. Sealing. Once activity stops, every opening is closed with metal mesh, flashing or sealant made for the spot.
4. Cleanup. Droppings and nests are removed, and soiled insulation is replaced if needed.

The full process is on our Rat Removal page.