8 Florida Spiders and What Their Bites Really Do
Florida has hundreds of spider species. Only the widows can make you seriously ill, and the big, alarming ones are almost never the problem.
Spiders do not hunt people, and they do not bite to feed on us. Nearly every bite happens when a spider is pressed against skin by accident: inside a glove, a shoe or a sleeve, under a hand reaching into a woodpile, or in bedding. Given any choice, a spider runs or drops out of sight.
Florida has several hundred species, and almost all of them have venom, because that is how spiders subdue insects. In nearly every case the venom is too weak, the amount too small or the fangs too short to do a person real harm. The usual result of a bite is a sore, red bump that fades in a day or two.
The exceptions are the widows. Florida has four species, more than most states, and their venom acts on the nervous system. A black widow bite can put a healthy adult in the emergency room with severe pain, and it is more dangerous for small children, older adults and pregnant women.
The spider most Floridians fear, the brown recluse, is the one they are least likely to meet. This guide covers eight spiders, from the ones to take seriously to the ones that only look the part, along with what a bite does and what to do about it.
Read all the way to the end. We save the biggest spider on the list for last, and it is the least dangerous.
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Take seriously
1. Southern black widow
Photo: Tom Sid / Unsplash Seen one at home?The female southern black widow is glossy, jet black and about half an inch long in the body, or an inch and a half across with her legs spread. The underside of her round abdomen carries a red hourglass, usually complete. Males are much smaller, brown and striped, and are not a danger to people.
She lives throughout Florida and builds an untidy, very strong web close to the ground in dry, dark, undisturbed places: woodpiles, sheds, water meter boxes, crawl spaces, stacked flowerpots, grills and the undersides of outdoor furniture. She hangs upside down in the web and retreats when disturbed. Bites happen when a hand closes on her or on her egg sac.
AdvertisementThe venom contains a toxin that forces nerve endings to release their chemical signals all at once. The bite itself feels like a pinprick or is not felt at all. Within about an hour, a dull ache spreads from the bite. Over the next several hours it builds into severe, cramping muscle pain in the abdomen, back, chest or thighs, often with sweating, nausea, headache, restlessness and a rise in blood pressure. The belly can become so rigid that the condition is mistaken for appendicitis.
AdvertisementSymptoms usually peak within the first day and ease over one to three days. Hospitals treat the pain and muscle spasm with strong pain relievers and muscle-relaxing medication, and an antivenom is available for severe cases. Deaths are extremely rare.
A black widow bite rarely leaves much of a mark. The illness is in the muscles, not the skin.
If you are bittenWash the bite with soap and water and apply a cool compress. Call Poison Control at 1-800-222-1222, and go to an emergency department if muscle cramps, belly or chest pain, or sweating develop. Children, older adults and pregnant women should be seen promptly in every case.Advertisement -
Take seriously
2. Northern black widow
Photo: Rafael Garcin / Unsplash Seen one at home?The northern black widow looks much like her southern relative, with two differences that are easy to see. The red hourglass on the underside is broken in the middle into two separate marks, and a row of red spots runs down the center of the back. Some females also have thin white lines on the sides of the abdomen.
In Florida she lives only in the Panhandle, mostly west of Tallahassee. Her habits differ, too. She prefers woodland and tends to build her web higher, in the low branches of trees and shrubs, in hollow stumps and under loose bark, well away from houses. People who meet her are usually hikers, hunters, and those cutting or gathering firewood.
AdvertisementThe venom acts in the same way as the southern black widow's, and the illness is the same: little to see at the bite, followed by spreading pain, muscle cramps, sweating and nausea that build over several hours and last a day or more.
Because this spider lives away from buildings, bites are less common than those of the southern black widow. Treatment at the hospital is identical.
AdvertisementIf you are bittenTreat it exactly as you would a southern black widow bite. Wash it, cool it, and seek medical care if pain spreads beyond the bite or cramping begins. -
Common
3. Brown widow
Photo: Alexandra Stam / Unsplash Seen one at home?The brown widow is now the widow that Floridians see most. It is not native. It arrived from overseas, was confined to south Florida for decades, and since the 1990s has spread across the state and the Gulf Coast. It thrives on buildings.
AdvertisementThe female is tan to dark brown, sometimes nearly gray, with banded legs and a geometric pattern of pale and dark marks on the abdomen. Her hourglass is orange or yellow-orange, not red. The surest sign is the egg sac: a cream-colored ball about the size of a pea, covered in small silk spikes, like a tiny sea mine. Black widow egg sacs are smooth.
AdvertisementLook for brown widows under patio chairs and table rims, beneath railings and mailbox lids, in the handles of trash cans, inside empty flowerpots, and around garage doors and playground equipment. They are timid. A disturbed brown widow usually curls up and drops to the ground.
Her venom is potent, but she injects very little, and the bite is usually far milder than a black widow's. Most people have sharp local pain, a red mark and some soreness that settles within a day. Cramping and whole-body symptoms occur occasionally.
AdvertisementIf you are bittenWash the bite, apply a cool compress and take an over-the-counter pain reliever if needed. Seek medical care if muscle cramps, widespread pain, nausea or sweating develop, and sooner for a child. -
Rare
4. Red widow
Photo: 7Angles Photography / Unsplash Seen one at home?The red widow is found nowhere in the world except Florida. It lives in the dry sand-pine scrub of the central ridge and the southeastern part of the state, a rare habitat that has largely given way to citrus groves and housing.
AdvertisementIt is a strikingly handsome spider. The head, body and legs are reddish orange, and the abdomen is black with red or orange spots ringed in yellow or white. The underside usually has one or two small red marks in place of a complete hourglass.
The red widow builds its web several feet off the ground in saw palmetto and scrub palmetto, rosemary and scrub oak. It rolls a palmetto leaflet into a cone as a retreat and spins a tangled sheet of web across the fronds. Because it lives in the open scrub and not in buildings, very few people ever come across one, and those who do are usually clearing land or walking off trail.
AdvertisementIts venom is a nerve toxin of the same kind as the black widows', and a bite should be expected to cause the same illness. Documented bites are almost unheard of.
If you are bittenTreat it as a black widow bite. Wash it, apply a cool compress, call Poison Control at 1-800-222-1222, and go to an emergency department if pain spreads or cramping starts. -
Overblamed
5. Brown recluse
Photo: Markus Blüthner / Unsplash Seen one at home?The brown recluse is blamed for more wounds in Florida than any other creature, and almost always wrongly. Its native range is the south-central United States, from Texas and Oklahoma east to western Georgia and north to the lower Midwest. Florida lies outside it. The spider is not established in most of the state. The few confirmed finds have been isolated cases, typically in a single building, traced to spiders carried in with furniture, boxes or freight.
AdvertisementA true recluse is a plain, light brown spider with a body about three-eighths of an inch long, long thin legs with no stripes or spines, and a dark violin-shaped mark on the front part of the body. The decisive feature is the eyes: six, arranged in three pairs, where most spiders have eight. Many harmless Florida spiders are brown, and several have violin-like marks, so color alone proves nothing.
AdvertisementMost sores diagnosed as "spider bites" in Florida are something else. The most common cause is a bacterial skin infection, particularly MRSA, a staph infection that produces a painful, red, swollen sore with a dark or pus-filled center. Others include infected insect bites, shingles, diabetic ulcers and reactions to medication. The distinction matters, because a staph infection needs drainage or antibiotics and can spread to other members of a household.
AdvertisementWhere the brown recluse does live, most of its bites heal on their own with basic wound care. A minority develop a sunken, darkening sore over several days that takes weeks to heal.
If you did not see a spider bite you, the odds are that a spider did not bite you.
If you are bittenAny sore that grows, darkens, drains or will not heal needs a doctor, whatever caused it. Spreading redness, warmth, fever or red streaks point to infection and need care the same day.Advertisement -
Looks scary
6. Golden silk orb-weaver
Photo: michael podger / Unsplash Seen one at home?This is the "banana spider" of Florida's woods, and it is the largest orb-weaving spider in the country. The female has a long, cylindrical body about an inch to an inch and a half long, silvery on the front, with a dull orange or olive abdomen dotted with pale spots. Her legs are banded in yellow and brown, with tufts of dark hair like bottle brushes. With legs extended she spans four inches or more. The male is tiny and often sits unnoticed in the same web.
AdvertisementHer web is the remarkable part. It can be three feet across or more, slung between trees at head height, and the silk has a distinct golden sheen in sunlight. It is strong enough to feel a real tug when you walk into it. Webs are at their largest from midsummer through fall, along trails, forest edges and the eaves of houses.
She is not aggressive, and she stays in the web even when it is touched. A bite takes real provocation, such as pinching her in a hand.
AdvertisementA bite causes sharp local pain and redness, like a mild bee sting, and fades within hours. Her venom is not dangerous to people.
If you are bittenWash the bite with soap and water and apply a cool compress. Nothing more is needed unless you have signs of an allergic reaction, such as hives, facial swelling or trouble breathing, which call for 911. -
Looks scary
7. Wolf spider
Photo: Marino Linic / Unsplash Seen one at home?Wolf spiders are the large, brown, hairy spiders that sprint across garage floors and patios. Florida has many species. The largest, the Carolina wolf spider, has a body an inch long or more and a leg span of three to four inches. They are mottled in brown, gray and black, often with a pale stripe down the body.
AdvertisementThey build no web. They hunt on foot at night, running down crickets, cockroaches and other insects, and they have excellent eyesight. Shine a flashlight across a lawn after dark and their eyes glitter back like drops of dew. The female carries her round egg sac attached to the rear of her body, and when the young hatch they ride on her back for a week or more.
AdvertisementWolf spiders come indoors by accident, under doors and through garages, most often in fall. They are fast and startling, but they are not aggressive, and they bite only when trapped or handled.
The bite can be painful because the fangs are large. It causes redness and swelling that can last a day or two, sometimes with itching. The venom has no serious effect on people and does not cause skin to die.
If you are bittenWash the bite, apply a cool compress and take an over-the-counter pain reliever if needed. See a doctor only if swelling keeps spreading after 24 hours or signs of infection appear.Advertisement -
Looks scary
8. Huntsman spider
Photo: Sonika Agarwal / Unsplash Seen one at home?The huntsman is the spider that produces the loudest reaction in Florida homes. It is flat and light brown, with a body about an inch long and long legs that splay out sideways like a crab's, spanning three to five inches. A pale band runs across the front of the face. It is not native. It came from Asia long ago and now lives across the warm parts of the world, including central and south Florida.
AdvertisementIts flat shape lets it slip into narrow spaces: behind picture frames and wall clocks, under loose bark, in sheds and barns, behind sun visors in cars. It builds no web and hunts at night. It is extremely fast, and it can run across walls and ceilings.
It is also one of the most useful animals that could move into a Florida house. Its main food is cockroaches, including the large ones, and it eats other spiders, silverfish and crickets too. It cannot survive cold winters, which is why it stays in the southern half of the state.
AdvertisementA huntsman would much sooner run than bite. When one is pinned or grabbed, the bite causes brief, sharp local pain and mild swelling that settles within a few hours.
If you are bittenWash the bite and apply a cool compress. To remove the spider, place a container over it, slide stiff card underneath and release it outdoors.
The short version
Of the hundreds of spiders in Florida, only the widows cause serious illness, and even their bites are almost never fatal. Learn what they look like: a shiny black spider with red marks, or a brown one with an orange hourglass and spiky egg sacs. The brown recluse is not established in most of the state, and the big spiders that cause the most alarm are harmless.
Prevention is simple. Shake out shoes, gloves and clothing that have been stored in a garage or shed. Wear gloves when moving firewood, boxes, flowerpots and patio furniture. Look before you reach under a ledge or into a meter box. Clear webs and egg sacs from outdoor furniture with a broom or a vacuum.
For any bite, wash it and apply a cool compress. Get medical help for muscle cramps, belly or chest pain, heavy sweating, trouble breathing, spreading redness, or a wound that keeps getting worse. Poison Control answers at 1-800-222-1222 at any hour and will tell you whether you need to be seen.
Last updated . This article is for general information and isn't medical advice. In an emergency call 911.
