1.
Spiders
(1) Spiders are amazing. They are part of a special group of animals. These are called invertebrates. That is any animal that does not have a backbone. Some do not have any bones at all, like worms. Some have their skeletons on the outside. Spiders are one of these animals. They have a shell on the outside Animals that have a backbone are called vertebrates. They include humans and many other mammals.
(2) Spiders are not insects. Some people lump in spiders with all kinds of bugs. This is not right. Spiders belong to a group called arachnids [uh-rak-nidz]. These are animals with soft bodies and eight legs. Insects have only six legs. Spiders have eight legs, so they are not insects.
(3) In fact, spiders eat many insects. This is one way that spiders are helpful. They catch bugs in their webs. Some of the bugs they eat are flies and mosquitoes. Flies can get into our food. They carry germs. And, as you know, mosquitoes bite! They carry germs too. The more spiders you have near your house, the more bugs they will eat!
(4) Still, it is good to be careful around spiders. Some spiders are dangerous. A few are poisonous. If they bite you, you could get very sick. Some spiders do not have poison in their bite, but it still hurts if they bite you.
(5) Spiders have impressive skills. They can jump quite far. Some can jump up to fifty times their body length! They also spin webs. They create a kind of silk from their bodies. It is strong and sticky. The spider weaves the silk into a pattern. This web is like a net that catches insects that walk or fly too close to it. The bugs stick to the silk, and then the spider can come out and wrap them up. Using the same silk, the spider wraps up its meal, so it can eat the bug later.
1. Based on information from the passage and the examples in the table below, what does the word invertebrate mean?
