Yellow Sac Spiders are surprisingly more aggressive than most Utah arachnids. They are responsible for most of the spider bites that are found when waking up in the morning. The bite is know as Cytotoxic, meaning it causes skin death in small areas where the bite takes place. It can be compared to Hobo or Brown Recluse spider, just not as toxic. The bite will cause a small red bump on the skin.
The months of April-October are the heavy outdoor season and they migrate inside the home the remaining months of the year.