Arizona has lots of bugs and insects. Because the desert is so dry and hot crickets, scorpions, spiders, ants, silverfish, roaches, springtails, and other bugs, that come either from the desert or your plants, get in your yard, and get in your house. Phoenix, AZ is no exception, hundreds of people have reported being stung by scorpions, and hundreds are living with black widows, and roaches.
Here in the desert in Arizona, we have only a few species of insects; like scorpions, some of the spiders that crawl in the ground, and a few kinds of ants. However, we've brought in quite a few different species through nurseries and packaging.
Once you take a plant home from the nursery, frequently within the soil of that plant, there are numerous types of roaches, spiders, silverfish, earwigs, that are not indigenous or natural to this environment.
However, the added water that we place at the base of these plants once they're planted, makes it a tropical environment for these organisms to live in, and they thrive in that environment, as do all the scorpions from the desert which come in for the added food. Once they thrive inside your house, its only a matter of time before they pressure inside your home.