Tip/Thought of the Day

4 Critters Of The Southwest To Avoid

We’ve previously shared information about honey bees; in large swarms, aggressive bees can be a danger to you and your family. Many of us have also encountered other insects and creatures that we’d rather not have as regular visitors in our homes. Here are four critters to avoid, and how to prevent them from setting up house on your property.

Black Widows

Black Widow
Image courtesy of environmentalpestcontrol.com

Earning their name because the females will often eat their partner’s after they’ve mated, the female black widow spiders are striking with their shiny black bodies and distinctive red “hourglass” on the underside of the abdomen. Considered one of the most venemous spiders in North America, black widows are typically found in dark places, tucked in corners, under ledges, and build their irregular webs in spaces relatively close to the ground. They are most active at night, so exercise caution in the evening hours. 

They’re also big: A female is about 1.5 inches long. The male is less than half the size of the female, medium brown with cream-colored markings on legs and abdomen. The young of both sexes resemble the male.

Western Black Window
A female black widow (top) and a male (bottom)

You can use a bug repellent spray to prevent black widows from settling in, but chances are you wont be able to completely prevent spiders from coming near your home. The best advice is to seal up any holes (install door sweeps, weather stripping) to prevent them from entering your home, and keep outdoor areas free of debris. Maintain these common hiding spots clear of webs and inspect before handling:

  • Children’s toys that are kept outdoors (the underside of bike seats, the edges of sand boxes, etc).
  • The underside of garbage can handles
  • Storage sheds
  • Wood piles
  • Brush or plants that are low-laying

Black widow venom is roughly 15x stronger than that of a Rattlesnake. But, despite the potency of venom, the chances of a healthy adult dying as a result of a black widow bite are low. In fact, not all bites from a black widow spider result in envenomation. These spiders can choose when to inject venom into their perceived attackers, and how much to inject. If the threat is less severe, researchers have found that the black widow may deliver what’s known as a dry, or nonvenomous bite. It’s thought that this calculation is made in order to preserve venom for prey. Still, bites can be dangerous to children and the elderly. Anyone who is bitten needs protection from tetanus. If you haven’t had a tetanus booster shot in the last five years, call your provider. 

Chest and muscle pain are the two most common symptoms, but black widow spider bites can also lead to nausea, vomiting, convulsions or unconsciousness. It is recommended that if somebody is bitten by a black widow, to call Poison Control (800-222-1222) if the symptoms appear to be mild, but seek medical attention if you are unsure, or if the person that was bitten is a child or elderly.  

Brown Recluse Spiders

The brown recluse spider is the most common brown spider, but is usually only found in the south and central United States.

The brown recluse’s shape is distinctive, having a violin shaped body. The violin marking can vary in intensity depending on the age of the spider, with mature spiders typically having dark violin shapes. The recluse’s eyes are one of its most distinctive physical characteristics. “They have six eyes, instead of eight like most spiders,” said entomologist Christy Bills, invertebrate collections manager at the Natural History Museum of Utah.

Male southern house spider (left) photo by Sam Heck, licensed under CC BY-NC 2.0. vs. brown recluse (right), photo by Alex Wild

Brown recluse are most active at night. During the day they rest in hidden locations within the structures they infest. They are fond of building their retreats and resting on wooden surfaces, such as inside furniture, cardboard boxes, wall voids and in the wood framing of crawlspaces, basements and attics. They are not often found far from structures. Once brown recluse have built a home, it is difficult to remove them, so prevention is key. To keep these critters out of your home, the best thing is to prevent access.

Cracks and crevices should be sealed with caulk, expandable foam, weather stripping, screen or other materials to prevent the spiders from entering them and gaining access to structural voids. Seal around fireplaces, vents, door and window frames, crawlspace and attic doors, and where cabinets, counters and baseboards meet walls, to permanently prevent brown recluse, and other pests as well, from harboring there.

If you or somebody else is bitten by a brown recluse spider, symptoms may include:

  • Pain or redness at the site of the bite
  • A deep sore that forms where you were bitten, with the skin at the center turning purple
  • Fever
  • Chills
  • Nausea
  • Joint Pain
  • Weakness
  • Seizures or coma (very rare)

Serious skin reactions may occur, including damage to the tissue surrounding the bite. The image below shows a reaction commonly associated with the brown recluse bite.

Image courtesy of: spidersinfo.com

You should immediately call your doctor or go to the emergency room if you believe a brown recluse spider has bitten you. Prompt treatment is especially important for children or elderly people, because they often have more severe symptoms. As you make your way to the doctor’s office or ER:

  • Wash the bite wound with soap and water as soon as possible.
  • Elevate the area where the bite occurred.
  • Apply a cool compress or ice pack to the bite to help with swelling and pain — 10 minutes on, then 10 minutes off.


It wouldn’t be the Southwest without scorpions. These interesting critters have venom that is a neurotoxin, used to subdue prey and during the mating process as well. Scorpions, like black widows, are able to regulate the amount of venom used, depending on the size of the threat or prey. Most scorpion stings are not considered life threatening to humans — the exception is the sting of the bark scorpion, the most venomous in the United States.

Scorpions are predatory and are most active at night, but choose to stay under rocks or other objects during the day. They often ambush their prey, lying in wait as they sense its approach. They consume all types of insects, spiders, centipedes and other scorpions. Larger scorpions may feed on vertebrates, such as smaller lizards, snakes, and mice if they are able to subdue them. They capture their prey, paralyzing them with their venom as well if necessary. The immobilized prey is then subjected to an acid spray that dissolves the tissues, allowing the scorpion to suck up the remains. Sounds pleasant, right?

Luckily, most scorpions stings aren’t deadly for most adults, but they can be lethal to children or the elderly. Most scorpion stings cause only localized signs and symptoms, such as pain and warmth at the site of the sting. Sometimes these symptoms may be quite intense, even if you don’t see redness or swelling.

The same advice for preventing unwanted encounters with black widows and brown recluse applies to scorpions; keep debris and brush clear from around your home and yard, and be cautious when reaching into or overturning items that could be hiding spots for critters.

Signs and symptoms at the site of the sting may include:

  • Pain, which can be intense
  • Numbness and tingling in the area around the sting
  • Slight swelling in the area around the sting

Signs and symptoms related to widespread (systemic) venom effects usually occur in children who are stung and may include:

  • Difficulty breathing
  • Muscle twitching or thrashing
  • Unusual head, neck and eye movements
  • Drooling
  • Sweating
  • Nausea and vomiting
  • High blood pressure (hypertension)
  • Accelerated heart rate (tachycardia) or irregular heart beat (arrhythmia)
  • Restlessness or excitability or inconsolable crying (in children)

At-home care of a scorpion sting includes:

  • Wash the sting with soap and water and remove all jewelry. Swelling of tissue may impede the circulation (for example, a sting on a finger that has a ring surrounding it).
  • Apply cool compresses, usually 10 minutes on and ten minutes off of the site of the sting.
  • Acetaminophen (Tylenol) 1-2 tablets every 4 hours may be given to relieve pain
  • Avoid aspirin and ibuprofen (Advil, Motrin) because they may contribute to other problems.
  • Antibiotics are not helpful unless the sting area become secondarily infected.
  • Do not cut into the wound or apply suction.
  • If a child is 5 years or younger is stung, seek evaluation by a medical caregiver.

As with other stinging insects, such as bees and wasps, people who have previously been stung by scorpions can also have allergic reactions with subsequent stings. Subsequent stings are sometimes severe enough to cause an anaphylactic reaction, which can be deadly if not treated immediately. Hives, trouble breathing, and nausea and vomiting are all symptoms that are alarming, and you should seek immediate treatment. If a child is stung by a scorpion, seek immediate care.

If you are concerned about a scorpion sting that an adult has experienced (but they aren’t experiencing anaphylactic symptoms, you can also call Poison Control (800-222-1222). If you are stung and begin to experience any symptoms like an irregular heart beat or symptoms of anaphylaxis, seek care immediately (or call 911).

Sonoran Desert Toad

The Sonoran Desert Toad (also known as the Colorado River Toad) is native to Arizona, and is the second most toxic toad in the world. Luckily, they are only emerge from the ground during the monsoon season as the moisture comes through our area and are nocturnal, so it isn’t often that you or your pets will encounter them during the day. But, during the monsoon season, if pets come into contact with the toads and their poisonous glands (found right behind their eyes), it could mean serious trouble for their health. While not a huge threat to people (wash your hands if you somehow touch one), pets may experience symptoms like

  • pawing at their mouth and eyes
  • crying and whimpering
  • difficulty breathing
  • the membrane in their mouth may change color
  • seizures
  • temperature
  • drooling

If you notice your pet is experiencing these symptoms and may have come into contact with a Sonoran Desert Toad, thoroughly rinse their mouth out with a garden hose and seek veterinary care.

Standing water often dries up before eggs can hatch or tadpoles develop into frogs capable of surviving on land, so they frequently die. If the monsoon season is short or not very wet, it is likely that there are few successful breedings and the species must wait until the next monsoon to reproduce. Knowing their preferred habitat is stagnant water, remove items that can catch and hold rain (like empty flower pots or trash cans, pond-like collections of water on the ground, etc), and also make sure to run your pool pump regularly to deter egg-laying.

Since Sonoran Desert Toads love the rain and moisture, they seek out those ideal conditions and for a series of rainy days to lay their eggs which can be up to 8,000 at a time! If you notice a slimy, stringy mass in your pool or in standing water, remove it immediately, or you’ll soon have quite a mass of visitors. Removing them is important as the metamorphosis from egg to taddpole to toad takes less than a month for Sonoran Desert Toads. Some other species of toads found in the Southwest can change from “tadpole to hopper” in as little as a week!

Sonoran Desert Toad eggs are deposited in rope-like structures. Photo courtesy of erowid.org

Caution is the name of the game when it comes to critters of the Southwest. Black widows, brown recluse, and scorpions aren’t looking for a fight with humans, nor toads with our pets- in fact, they want to avoid contact considering it is likely a losing battle. If they are threatened though, a bite or sting may be their only recourse. Exercise caution in areas that they consider cozy- dark crevices, away from activity. An often overlooked detail: avoid leaving shoes, gardening gloves, or clothing outside as they can sometimes be mistaken as a nice home for creatures.















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