Spiders are a type of insect that is classified as ‘Arachnida’. They are different from other types of insects because they have only two main body parts as opposed to three in other insects. A lot of people are afraid of spiders, while others keep them as pets.
Interesting facts about spiders:
A spider’s body has a combined thorax and head that is call the cephalothorax. The second part of their main body is the abdomen.
- It is believed that spiders have been on the earth for over 300 million years.
- While Arachnida include spiders, mites, scorpions and ticks, spiders are in a sub-classification that is called “Araneae” that separates them from the others. The difference includes a waist that is slender, offering an abdomen separation.
- A spider’s body is enclosed in an exoskeleton called a ‘carapace’ and a lot of the body has small hairs growing from the skin that are very sensitive.
Spiders have claws at the end of each of their segmented legs. Some have two claws and some have three claws. Those that have three claws are typically web-building spiders and the middle claw has a way to help them hang on to its web by using a tuft of hairs.
Spiders have muscles and blood that circulates through their body. Their circulatory system doesn’t have capillaries as we do, but they do have arteries, a heart and veins. Their blood is a pale blue color due to a chemical called haemocyanin.
Many spiders can bite by using the fangs that extend below their two small jaws. They have glands that are located behind the jaws that contain venom or poison. The purpose is to kill or paralyze their prey. Most venom is not harmful to people, with the exception of the Black Widow and the Brown Recluse in the United States.
There are spiders around the world that have venom that can cause pain in humans. The South American wolf spider, West African Pigeon spider are two types. Australia seems to have a large population of species that are venomous, with the Sydney funnel-spider and the red-black spider as two that can be dangerous to humans.
A spider’s venom does not have the same effect on all animals. Keep cats and horses away from Black Widows as they are susceptible to the bite, however dogs don’t seem to be bothered and rabbits and sheep are immune.