Look at the body. A spider has two clearly separate body parts, a front section where the legs attach and a rounder abdomen behind it, joined by a narrow waist. A tick looks like a single flat, oval, seed-shaped piece with small mouthparts sticking out the front and no visible waist. Ticks also crawl slowly, cling to skin, hair or fur, and never spin webs.
Both are arachnids, and both have eight legs as adults, so counting legs won’t settle it. Body shape and behavior will.
Spider vs tick: side-by-side #
| Feature | Tick | Spider |
|---|---|---|
| Body | One fused, flat, teardrop or oval shape | Two parts with a narrow “waist” between them |
| Head | No obvious head; mouthparts poke forward like a small beak | Front section with a cluster of eyes, fangs underneath |
| Legs | 8 on adults and nymphs, 6 on newly hatched larvae | 8 |
| After feeding | Swells like a gray or tan bean, legs look tiny | No change you’d notice |
| How it moves | Slow, deliberate crawl upward; doesn’t jump | Usually quick, or sits still in a web; jumping spiders hop |
| Where you find it | Attached to skin, crawling on clothing or a pet after time outdoors | Corners, webs, under furniture, running across the floor |
| Webs or silk | Never | Yes (spinnerets at the tip of the abdomen) |
If the thing is embedded in your skin with its head buried, it’s a tick. Spiders bite and let go; they don’t stay attached.
How to check a tiny one #
Very small ticks (nymphs) are about the size of a poppy seed and easy to mistake for a speck of dirt or a baby spider. A few quick checks:
- Use your phone’s camera as a magnifier. Zoom in or use macro mode and look for a waist. No waist means tick or mite.
- Look at the front end. A tick’s mouthparts form a little point at the front. A spider’s front half is broad and rounded.
- Watch it move on white paper. Ticks crawl steadily and try to climb. Spiders dart, stop, and dart again.
- Check the back. Hard ticks have a shield (scutum) near the front of the back. On a female lone star tick, the CDC notes a single white dot, the “lone star.”
Other bugs that get mistaken for both #
- Mites. Tiny reddish clover mites crawl onto sunny windowsills in spring and fall. The University of Kentucky describes them as moving dark spots to the naked eye that leave red-brown stains when crushed. They don’t bite people and die soon after coming indoors.
- Harvestmen (daddy longlegs). Eight very long legs and a single round body with no waist, which makes them look like a tick on stilts. They don’t bite people and are harmless.
- Chiggers. Larval mites that are nearly invisible. You’ll notice the itchy welts around ankles and waistbands, not the mite.
- Bed bugs and spider beetles. Both are insects with six legs. Bed bugs are flat, oval and brown, a bit like an unfed tick, but they don’t attach; see bed bug vs carpet beetle for the other common mix-up.
If it’s a tick: remove it the CDC way #
Don’t wait to identify the species if it’s attached. The CDC’s instructions are simple:
- Grasp the tick as close to the skin’s surface as possible with clean, fine-tipped tweezers.
- Pull upward with steady, even pressure. Don’t twist or jerk, which can leave mouthparts in the skin.
- Clean the bite and your hands with soap and water, rubbing alcohol or hand sanitizer.
- Dispose of the tick by putting it in a sealed container or alcohol, wrapping it tightly in tape, or flushing it. Don’t crush it with your fingers.
Skip petroleum jelly, nail polish, heat or other tricks to make the tick back out. The CDC advises against all of them.
Saving the tick in a sealed bag or taped to an index card, with the date and where you think you picked it up, is useful if you get sick later. If you develop a rash or fever within several weeks of removing a tick, the CDC says to see your doctor and tell them about the bite.
Which tick was it? #
The species matters because different ticks carry different diseases. According to the CDC:
- Blacklegged (deer) tick, eastern US: Lyme disease, anaplasmosis, babesiosis, Powassan virus and others.
- American dog tick, east of the Rocky Mountains: Rocky Mountain spotted fever and tularemia.
- Lone star tick, Northeast, South and Midwest: ehrlichiosis, tularemia, STARI and alpha-gal syndrome, among others.
Our deer tick vs dog tick guide covers how to tell the common ones apart. The University of Rhode Island’s TickEncounter program also runs TickSpotters, where you can submit a tick photo for identification by people who study them.
If it’s a spider: most are harmless #
The vast majority of spiders you’ll find at home are harmless to people and eat other pests. In the US, the two spiders that deserve real caution are the black widow (shiny black with a red hourglass under the abdomen) and the brown recluse (tan to brown with a violin-shaped mark and six eyes in pairs, found mainly in the south-central and Midwestern states). Our brown recluse vs wolf spider post covers the most common recluse mix-up.
If someone is bitten by a spider and has spreading pain, cramping, a growing wound, or feels ill, get medical advice promptly. In the US, Poison Control is free and confidential at 1-800-222-1222. Call 911 for trouble breathing or signs of a severe allergic reaction. If you can safely capture the spider in a jar, bring it along; the University of Kentucky points out that many other conditions get blamed on recluse bites, and a specimen helps.
Using a photo to check #
A sharp, close photo is often enough to tell a tick from a spider, and to narrow down which one. Insect Identity can do that first pass offline on your phone: its 224 species include the deer tick, American dog tick and lone star tick, plus the black widow, false black widow, brown recluse, wolf spider, common house spider, bold jumping spider and yellow garden spider. You get a best match with a confidence score and four runners-up, so a split vote between a tick and a spider tells you to look closer.
Know its limits. It doesn’t include the brown dog tick, Gulf Coast tick, mites, chiggers or harvestmen, a swollen engorged tick can look very different from the unfed adults it learned from, and no app should decide whether you need a doctor. Use it to name what you found, then follow the CDC and Poison Control guidance above for anything that bit someone.
Frequently asked questions #
Do ticks have six or eight legs? #
Adult and nymph ticks have eight legs, like spiders. Newly hatched tick larvae have six, which is why they’re sometimes mistaken for tiny insects.
Is a tick a type of spider? #
No. Ticks and spiders are both arachnids, the same broad group that includes mites and scorpions, but they’re in different orders. Ticks are more closely related to mites.
What does a tick look like after it has fed? #
A feeding tick swells dramatically, turning from a flat brown or reddish seed shape into a rounded gray, tan or bluish bean. The legs stay the same size, so they look tiny next to the body. An engorged tick can be mistaken for a skin tag.
What tiny bug looks like a tick but isn’t? #
Clover mites, spider beetles, bed bugs and some small beetles are common mix-ups. The fastest tell is behavior: only ticks latch onto skin and stay attached.