They are called recluse spiders because they are reclusive, meaning that they do not like to be seen. They are nocturnal, so they are awake at night, and are more likely to run from you than strike. They will only bite out of self-defense.
Brown recluse spider bites are most likely to occur when the spider gets trapped against your skin. In many cases, the spider has crawled into a clothing item or a shoe and bites when you put the item on.