Life Cycle of a Spider

Spiders are arthropods.  They have a hard exoskeleton.  But they’re not insects because they have eight legs instead of six.  They are in their own class: Arachnida.  Arachnids are predators and carnivores.  They often kill their prey with poison and then spit digestive juices from their stomachs onto the body of their dead prey, dissolving it before sucking up the pre-digested juices.  Learn about the life cycle of a spider with us.

Black widow spider, Photo by Chuck Evans. CC license.

Black Widow Life Cycle

Black widow spiders mate in spring and early summer.  The male is about half the size of the female.  Though the black widow does sometimes eat her mate after breeding, this is not always or even usually the case.  When the female black widow does feed on her mate it is because she is low in nutrients and needs the energy.

Image by John D. McCrone and Herbert W. Levi, CC license

After mating, the female black widow weaves a round or pear shaped nest of silk into which she deposits her eggs.  The web of the black widow is random and messy looking, not symmetrical and neat like some spiders.  Female black widows can mate and lay three or more egg sacs a season.  Hundreds of eggs are laid in each egg sac.  The mother black widow guards the egg sac for up to a month until it hatches.

Photo by Jengod, CC license

When the baby spiders hatch they begin to eat one another for nutrients, so only a few from each egg sac survive.  The survivors leave the egg sac within a couple of days of hatching.  When they leave they often “balloon”.  The baby spiders spin a long filament of web and it catches a breeze and floats them away from home.

From Wikimedia, CC license

The baby spiders molt several times over the summer and fall.  Over winter they mature and in the spring they are ready to find their own mates and start the cycle over again.  Most black widows live only one year, but they can live up to three years.

Photo by Lhollowood, released into the public domain.

Black Widow Movie

Watch this video of a black widow and its life cycle.

Spider Life Cycle Worksheet

Color the Life Cycle of a Spider worksheet.

Most spiders have a life cycle similar to the black widow, but they each have unique features.  The cannibalism of the black widows is unique, for example.

Additional Layers

  • Besides spiders, Class Arachnida includes scorpions and mites.  Learn more about these animals.
  • Writers Workshop: A lot of people are very afraid of spiders.  They bite and the way they move is spooky.  Are you afraid of spiders?  Write about an animal you are afraid of.  Describe in detail what about that animal scares you.
  • Learn which dangerous spiders live in your area and how to identify them.  Learn what to do if you get bitten.  Some spider bites are very dangerous and painful.
  • Search the Internet for a fun spider themed art project or craft to do.

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