White-throated Wood Rat, aka ‘Pack Rat’ (photo by Jim Cloer)

A lot of folks live in Arizona for a lot of reasons.  Many people who retire here, like most of us in SaddleBrooke, came from somewhere else, often somewhere dramatically different.  Like, almost everywhere else.  We move here to escape crowds, clouds and cold.  We leave beautiful places, family and friends.  Sunshine brings us here, like moths to a flame.  Year-round outdoor living:  walking, hiking, biking, swimming, pickle ball, tennis, golfing and more.  To enjoy all this, we tolerate hot summers, spiny stick-yous and scary stuff like snakes and scorpions.  But we draw the line at pack rats.

What is a ‘Pack Rat’ and Why do they Bring out our Killer Instinct?

To be accurate, what we call ‘pack rats’ are White-throated Wood Rats (Neotoma albigula), but let’s call ‘em pack rats;  it will keep the article shorter.  Pack rats are as cute as pet rats, important native desert mammals, not venomous and won’t bite.  What’s not to like?  Well, from a people perspective, quite a few things.  Pack rats crank out a lot of urine and fecal pellets, and spend more time chewing than a baseball player.  They chew cholla and mesquite pods for food and water, and just about anything else to keep their teeth honed.  Unfortunately for homeowners this includes wiring, cables and irrigation tubing in your yard, air-conditioning unit, hot tub, swimming pool equipment, car, attic and garage.  They also multiply like rabbits.  One female can produce two babies every two months, and a newborn female can start the same production line in just two more months, blessing us with a ten-fold population jump each year.

Having lived a perilous life in the open desert for millennia, pack rats view a desert community like SaddleBrooke like a nine-year old looks at Disneyland.  Well-watered landscaped yards offer shelter from the storm.  Here they find fatter cactus, fewer predators and lots of stuff to chew.  We prefer the comforts of home, and so do they.

How do You Keep Pat Racks from Choosing Your House?

Wherever you live, pros come with cons.  The forests of Oregon come with the gray skies and rain that keep them lush, and sunny Arizona deserts come with pack rats.  As much as we might hate them, rats are a necessary part of the food chain, a key element in the diet of owls, hawks, bobcats, coyotes, ringtails and other wildlife.  They also got here before we did, though that’s never cut much ice.  Nevertheless, we can still make our place less attractive to these little buggers.

Rats are nocturnal feeders and hide out during the day.  They like dark hideaways, clutter and cactus and hate sunshine.  Think Dracula.  To stay off their ‘A’ list, keep your property open and light and your attics screened.  Clear stacks of boxes, debris and junk.  Eliminate accessible hideaways.  Clear seed pods and leaves.  Don’t leave pillows and cushions outside.  Don’t put a loose cover over your grill.  And don’t even think about using poisoned rat bait.  By necessity, rat poison is rat food, and if bird food attracts birds, guess what rat food attracts.  There are many reasons not to use poison, but this is reason enough.  Poisoned bait will bring many more rats to your house than it will kill.  This is like putting mosquito repellent on your naked body and going outdoors in Minnesota.  Adding insult to injury, poisoned bait boxes are one of the pack rat’s favorite nesting spots.

How do You Eliminate Pack Rats?

Follow the above advice and your house won’t be a rat’s first choice.  Even so, you may experience a pack rat.  If you find fecal rat pellets, chewed pillows or hear the patter of tiny feet in your ceiling at night, you’ve got one.  That creepy ceiling scurrying means you need to rescreen your eaves, but rats aren’t playing house there.  They nest outside near their food, and only come inside to gather nest material and chew stuff up.  You need to do two things:  get rid of the rats and get rid of their nest.   If you have a nest, you can kill rats till the cows come home, while new arrivals continue to use the nest. 

First, get rid of the rats you have by killing them in a disposable trap or catching them in a live trap.  Give those caught in a live trap to our local, licensed naturalist, Jim Cloer.  He euthanizes and freezes them for rehabilitating raptors.  You can also feed them to predators indirectly by releasing them in the desert.  For the squeamish, Jim provides baited traps and retrieves the captured rats.  All traps should be set only at night to prevent killing inquisitive birds like Cactus Wrens. 

Second, get rid of nests, which often are easy to find—look for them in dark outdoor hiding places, like under cactus.  Look for accumulated seed pods, cholla or other unnatural conglomerations.  Clear them completely, seal them off or open them to sunlight.

Poisoning Rats Actually Increases the Rat Population

As illogical as it sounds, poisoning rats doesn’t reduce the number of rats, it increases it, and by a lot.  If your pest control company uses poison to control rats, you need a new pest control company.  Regardless of what they might say about the ‘safety’ or environmental soundness of any product they use, you don’t want any part of it.  There is nothing on the U.S. market today that is designed to kill pack rats, and the chemicals so used by pest control companies cause significant harm, without decreasing the number of rats.

Pack Rats will even Nest in Poisoned Bait Boxes (photo courtesy Mr. Pack Rat, Tucson, Arizona)

Poisoned rat bait attracts rats.  It will kill some, but there will be more in your yard after using poison than before.  Poisoned bait is slow-acting, and rats that die take a week or more to expire.  In the meantime, they get confused and sick, and are more vulnerable to predation.  Opportunistic predators like bobcats, Cooper’s, Red-tailed and Harris’s Hawks, Barn and Great Horned Owls, find these rats easily, suffering secondary poisoning in the process.  Many share this slow-acting time bomb with their families, causing a chain-reaction of destruction.  Not long ago, beautiful Great Horned Owls nested on a ledge outside the SaddleBrooke Clubhouse dining room.  The male brought a poisoned pack rat to the female who was incubating three eggs, killing her.  The three eggs were retrieved and incubated, but unsuccessfully.  No one knows what happened to the father, but if this happened to one of us, we’d commit suicide.

SaddleBrooke Bobcat, Victim of Secondary Rat Poisoning (photo by Jim Cloer)

This one example shows the population impact of a single poisoned rat.  In Arizona, rodents account for as much as 80% of the diet of owls and hawks, and a Great Horned Owl can eat a pack rat daily.  These owls live 28 years or more in the wild.  Assume that, on average, one owl consumes 300 pack rats annually for 25 years.  By killing four owls, this one poisoned pack rat prevented the natural depletion of pack rats by 1,200 each year for the next 25 years.  That includes 600 females a year that can bear 20 more each by Christmas, so add another 12,000 rats each year that were saved from natural extinction.  In other words, this single poisoned rat increased the population by saving thousands of other rats from death-by-owl.  Talk about martyrs.  They probably built a statue to this guy in rat town. 

Incidentally, poisoned rats that die in your ceiling space disintegrate and smell really awful.  And like the signs in the pit toilets say, removing stuff that doesn’t belong there is not easy.

Are there Alternatives to Commercial Poisoning of Rats?

For those of us who don’t want to mess with rats personally, there are non-poison commercial alternatives.  Local companies that promote poison sometimes offer options such as kill or live trapping, but a rat control service that offers a poisoned bait option is as moronic as it is oxymoronic.  Companies that poison rats haven’t done their homework, and should stick with termite and pre-emergent weed control or whatever else they do well.  If enough of us refuse services that use rat poison, maybe they’ll learn to do rat control properly or drop it.  In the meantime, there are companies that do understand rat control.  Some of them specialize in rats and some control nothing but pack rats.  None of these firms use poison, and some back their work with a guarantee.  Senior and retired military discounts are available.  If you can’t find one of these poison-free firms on your own, contact us and we’ll give you some help.

Why did We Collaborate on this Article?

Juvenile Harris’s Hawk Killed by a Bait-poisoned Pack Rat (photo by Jim Cloer)

Both Jim Cloer and I have our own columns, and have addressed this same subject before, though separately.  A couple of weeks ago, together we captured a sluggish juvenile Harris’s Hawk that was wandering on the golf course, apparently too weak to fly.  If you’ve seen the Raptor Flight show at the Arizona Sonoran Desert Museum, you know how incredibly beautiful this bird is.  Unfortunately, he died that night, and the bird’s black vomit unmistakably implicated poisoned rat bait, most likely brought to him by his mother.  If this makes you sick, think how she feels.  Collaboration was an easy decision.  With knowledge, we can all control our pack rats, and prevent the unnecessary, unintended destruction of other wildlife.  We hope you’ll join us.

(Jim Cloer, who provided information and photographs for this article, is a retired naturalist, is active with the SaddleBrooke Nature Club, manages the Nature and Wildlife program at Catalina State Park, and provides rescue and rehabilitation for injured wildlife.)

The above article was originally published in the July, 2012 Saddlebag Notes Newspaper, SaddleBrooke, Arizona.  Copyright June 12, 2012, Bob Bowers.