Why Are Squirrels Dying in My Yard? The Likely Causes

Rodenticide, squirrel pox, mange, heat and simple road traffic account for most of it. How to tell them apart, and when several dead squirrels means act.

By Zakaria November 2, 2026 3 min read Save to Pinterest

A red squirrel eating at a wooden peanut feeder on a lawn — Photo: Oldiefan, Pixabay Content License, via Pixabay

On this page

One dead squirrel is ordinary. Several in a few weeks is a signal, and it is usually one of three things: poison somewhere nearby, a disease outbreak at a feeding station, or a heatwave.

The short answer

Most backyard squirrel deaths come down to secondary rodenticide poisoning, disease (squirrel pox and mange above all), heat stress, vehicle and window collisions, and cats. Several deaths in a short window points to poison, an outbreak spreading at a feeder, or extreme heat. Skin lesions around the eyes, mouth and feet indicate squirrel pox; thin, crusted, balding animals indicate mange; slow, uncoordinated animals that are unafraid suggest poisoning. Handle carcasses with gloves and report clusters to your regional wildlife agency.

Several in weeks = poison, outbreak, or heat
Crusty lesions round eyes and mouth — squirrel pox
Thin, bald, crusted skin — mange
Slow, uncoordinated, unafraid — likely rodenticide
Gloves to handle, and report clusters to your wildlife agency

Reading the signs

what you see	likely cause
Crusty wart-like lesions round eyes, mouth, nose, feet	squirrel pox — viral, contagious, often fatal
Thin, patchy coat, bare grey crusted skin, emaciated	mange — mite infestation
Slow, wobbly, unafraid, then dead a few days later	anticoagulant rodenticide
Found in shade, panting, in a heatwave	heat stress
Body intact, near a road or below a window	collision
Puncture wounds, partially eaten	cat, dog, hawk or fox
No marks, old animal, winter	ordinary end of life — squirrels live 5–10 years in the wild

Rodenticide, which is the one worth chasing

Squirrels are rodents, so bait put out for rats kills them directly. An anticoagulant takes several days to work, during which the animal is slow, poorly coordinated and conspicuously unafraid — which is why poisoned squirrels are often the ones people notice sitting in the open.

The wider problem is what eats them next. Owls, hawks, foxes, and cats that take a poisoned animal take the poison with it, and that is how a bait station in one garden kills raptors across a neighbourhood.

If you suspect poison

Keep pets and children away from carcasses, since a dog that eats a poisoned squirrel receives a dose. If a neighbour is baiting, it is worth a conversation about enclosed, tamper-resistant stations and about the secondary kill — most people have not been told.

Squirrel pox and mange

Both spread where squirrels concentrate, and the place squirrels concentrate in a garden is a feeder.

Squirrel pox — a virus. Crusty lesions, discharge, a hunched slow animal. Frequently fatal. Does not infect people or pets
Mange — mites. Thinning coat, bare crusted skin, severe weight loss. Animals often die of exposure in winter rather than the mites themselves

The standard response to either is the same and it is unwelcome: take the feeders down for several weeks, and clean them thoroughly with a dilute bleach solution before putting them back. Breaking the concentration is the only lever a garden owner actually has.

Heat

Squirrels cannot sweat and pant poorly. In a serious heatwave they sploot flat on cool surfaces, seek shade and shut down activity, and the ones that do not find water or shade die.

What helps, and costs nothing:

A shallow water dish in shade, refilled daily and scrubbed
Shade retained rather than cleared
Nothing else. Feeding more in heat does not help; water does

Handling and reporting

Gloves, or an inverted plastic bag over your hand
Double-bag the carcass
General waste, unless your local authority specifies otherwise
Wash hands thoroughly afterwards
Keep pets off it before and during

Report a cluster — several animals over a few weeks — to your state or regional fish and wildlife agency before disposing of them. They track outbreaks, they sometimes want to test, and they will tell you whether to stop feeding in your area.

One dead squirrel in a garden over a year is background. Four in a month is information.

Common questions

What kills squirrels in a backyard?

The common causes are secondary rodenticide poisoning, disease — squirrel pox and mange in particular — heat stress in summer, collisions with cars and windows, cats and dogs, and ordinary predation. Several dead squirrels in a short period usually means either poison somewhere in the neighbourhood or a disease outbreak, and the two can often be told apart by whether the animals show skin lesions.

What does squirrel pox look like?

Crusty, wart-like lesions around the eyes, mouth, nose and feet, often with discharge, and an animal that looks hunched and slow. It is a virus, it is contagious between squirrels, and it is frequently fatal. It does not infect people or pets. Bird feeders and feeding stations concentrate squirrels and so help it spread, which is why taking feeders down for a few weeks is a standard response to an outbreak.

Could my neighbour's rat poison be killing squirrels?

Yes, and it is one of the most common causes. Anticoagulant rodenticides are eaten directly by squirrels, which are rodents, and also kill them indirectly. A poisoned squirrel typically takes several days to die and often appears slow, uncoordinated and unafraid first. The same bait kills the owls, hawks, foxes and cats that eat the poisoned animals, which is the strongest argument against using it outdoors at all.

Should I remove a dead squirrel from my yard?

Yes, both to stop pets investigating it and to reduce flies. Wear disposable gloves or use an inverted plastic bag over your hand, double-bag the carcass, and put it in the general waste unless your local authority says otherwise. Wash your hands thoroughly afterwards. If you have several in a short period, report it to your state or regional wildlife agency before disposing of them — they sometimes want to test.

Can I catch anything from a dead squirrel?

The risk is low but not zero, which is why gloves and handwashing are the rule. Squirrels can carry fleas and ticks that leave a cooling body, and in a few regions ground squirrels are relevant to plague surveillance. Squirrel pox does not affect people. Keep pets away from the carcass, since a dog that eats a poisoned animal gets a dose of the poison.

Why would several squirrels die at once?

Three patterns cover most of it: a rodenticide placed nearby, a contagious outbreak such as squirrel pox or mange spreading at a feeding station, or a heatwave. The timing is the clue — poison and heat kill over days, disease over weeks with visible skin signs. Contact your regional wildlife agency if you find several; they track outbreaks and will tell you whether to stop feeding.

Backyard Weekly

Know what to plant, week by week

Join the weekly email for seasonal jobs, fixes for what is going wrong, and gear worth buying.

Not ready to subscribe? The planting calendar is free and needs no email.

By subscribing you agree to our privacy policy. Grow In Backyard will never sell your address.

A red squirrel on a wooden rail twisting to scratch its flank with a raised hind foot

Backyard Animals · Sep 21, 2026