When you hear the word spider, you may want to run, and there is a good reason for this. A spider is an insect that has eight legs and could potentially bite you. Some spider bites may even be poisonous and filled with venom. Studies estimate there to be approximately 43,678 spider species in the world today. One of the scariest and largest spiders is the tarantulas, and the size of this gigantic spider is approximately up to 3.5 inches. A spider tattoo is one of the most popular types of tattoo designs on the market today. This tattoo can mean many things. However, if an individual in jail or prison gets a spider tattoo, this is symbolic of being locked up in a cell. The web is considered to be the prison bars that are keeping the person behind bars, and represents the struggle of life which many people could relate to.