8. Yellow Sac Spider
Also known as Black-footed Yellow Sac Spider. It is noted for numerous spider bites all over the world. It releases a mild toxin upon biting. Clear off if you happen to encounter this spider because its bite will give you a sharp pain and leaves the injured area swollen with a blister. It is usually present in Canada and Australia. Its 1/4 inch body size and pale-yellow color make this tiny spider very difficult to spot.