Spiders belong to a group known as "arachnids." They're more closely related to scorpions, ticks and mites than insects. Distinguishing spiders from insects starts with understanding their differences.

Spiders have two distinct body segments: a head-and-thorax segment, known as a "cephalothorax," and an abdomen. Insects have three segments: the head, thorax and abdomen. Spiders have eight legs, six to eight eyes and no antennae, but insects have six legs, two eyes and two antennae. Another key difference is that spiders have fangs instead of insect-like jaws.

Adult spiders may be as small as a poppyseed or measure several inches across. Their colors and markings vary as well. Some common spiders include the following:

  • Brown recluse – Feared for their venomous bites, these spiders grow to 3/4 inch or more. Their bodies range in color from light brown to darkest brown. They're sometimes called violin or fiddleback spiders because of the violin-shaped marking on their backs. Brown recluse spiders have three pairs of eyes.
  • Black widow – Known for sometimes killing their mates, female black widows grow 3/8 inch long or more. Several different regional species exist, but they have brilliant red, hourglass-shaped markings on their dark abdomens. Black widows have eight eyes.
  • Yellow garden – A common sight in gardens and lawns, this spider's body measures more than 1 inch in length. From the top, the females are black with bright yellow back patches and reddish-brown legs. These spiders have four pairs of eyes.

In most spider species, males are smaller and less colorful. Baby spiders hatch from egg sacs in large numbers and look like small versions of adults.


Spiders feed on insects, not plants. They're typically found in garden debris or dark, moist spaces where insects congregate. Seeing spiders in your home may signal a bigger insect problem that drew spiders in from the outside.

Some spiders weave webs to catch their prey, but others hunt their food instead. Signs of indoor infestations include simple cobwebs or intricate webs, and egg sacs filled with new spider generations waiting to hatch.


Effective spider control targets spiders before they find their way inside — and controls the insect pests that draw them there. Amdro® brand has several products that kill spiders and other insect pests and provide residual protection:

  • Amdro Quick Kill® Outdoor Insect Killer, available in ready-to-spray and concentrate formulas, works in minutes to kill spiders by contact in lawns, landscape plantings and flower gardens. These products also treat foundations up to a maximum height of 3 feet. Then they keep protecting against spiders and more than 500 listed insects for up to three months.*
  • Amdro Quick Kill Lawn Insect Killer Granules II provides a simple solution to spider and insect issues outdoors. Apply the product with a standard lawn spreader, then water the treated area lightly. The formula kills spiders and up to 100 listed surface and sub-surface insects within 24 hours and keeps them away for up to three months.
  • Amdro Kills Ants & Spiders Granules are ideal for treating smaller plantings and your home's perimeter. Available in a convenient, resealable shaker bag, the ready-to-use granules kill spiders and up to 50 listed insect pests. Then they keep working against those pests for up to two months.


Spiders can't get inside unless they have a way in. It takes less than 1/16 inch hole for common spiders to squeeze through. Seal any openings in your home's foundation, and keep your property free of yard and garden debris that attracts insect pests.

* Except fleas, ticks and mosquitoes.

Always read product labels and follow the instructions carefully.
Amdro and Amdro Quick Kill are registered trademarks of Central Garden & Pet Company.

Is this not your insect?