While spiders typically do not cause structural damage to the home, there are a few ways they can cause harm, whether apparent or not. As most people know, when spiders feel threatened, they will often bite humans. Depending on the type of spider, this can lead to swelling, or in the worst cases, death. Some types of spiders can be harmful for plants by deterring bugs that would otherwise pollinate them. Last but not least, we usually don’t encounter most spiders in our home. In spring, spiders often begin to mate, and prefer to lay their eggs within warm areas, which can lead to worse spider infestations that can become far more obvious later on.