There are 29 different types of spiders native to southeastern Wisconsin and two (the brown recluse and black widow) are poisonous. Spiders are not insects for two main reasons- they have eight legs and two body segments. Each female spider lays eggs in an egg sack that can contain as many as 3,000 eggs. While commonly found in all parts of the home spiders infestations usually tend to be worse in basements and near window wells.