Sort Spiders and Insects

In this simple hands-on activity, little scientists explore and learn the differences between insects and arachnids.

Simple Science:  Insects have 6 legs and 3 body parts.  Spiders have 8 legs and 2 body parts, so they are not insects.  Spiders are arachnids.  Other arachnids include scorpions and ticks.

Ever wonder what a web is made of?  All spiders weave webs out of silk, which is like a thin piece of really strong string.  The silk comes out of a hole at the bottom of the spider’s body, where it has “spinnerets.”  A spider can weave a web in about an hour.

Ever wonder why spiders weave webs?  Most spiders weave webs to catch food.  Parts of their webs are sticky and insects sometimes get caught in them.  Once an insect is caught, the spider can wrap it up in silk so it can’t get away.  The spider will eventually eat the insect.

Ever wonder if all spiders spin webs?  Not all spiders spin webs.  Some spiders, like the wolf spider, tarantula, and trap-door spider typically catch their food in other ways.  These spiders often live in burrows, which are holes in the ground.  They might grab insects or other food as it comes by their burrow.  The trap door spider uses its silk to build a wall with a trap door on top that insects can fall in.

Ever wonder why spiders don’t stick to their webs?  When spiders make a web, some parts are made with dry silk and some parts are made with sticky silk.  The sticky silk is what insects get caught in.  The spiders know where the dry silk is and try to walk only on those parts.  If a spider does step on some of the sticky silk, they have oils on their feet that help them not to stick.