Watch where you’re stepping – statistically speaking, Phoenix is a haven for cockroaches.

A new study shows that Phoenix is fourth “roachiest” city in the U.S. Houston, San Antonio and Tampa were the only cities to rank higher.

Pest Gnome, a pest control resource, released its study this month. The company mined data from the Census, the Bureau of Labor Statistics, and the National Oceanic and Atmospheric Administration for 25 Metropolitan Statistical Areas, as well as climate info, to come up with its Top 25 list.

The metrics with weighted results focused on: the share of homes with signs of cockroaches in the past 12 months; the historical average number of extremely hot days; and the number of pest control workers per 10,000 households.

According to the American Lung Association, cockroaches can worsen asthma and cause allergic reactions in people who are sensitive. Cockroach allergens can be found in their body parts, saliva, and fecal matter. These tiny particles can become airborne and contaminate the air indoors.

Furthermore, the ALA explains that cockroach allergens act like dust mite allergens and quickly settle. These allergens do not remain airborne for long. Activities like vacuuming may stir up allergens that have settled in dust or fabrics.

The most common way to inhale cockroach allergen is to breathe in dust that has collected in pillows, bedding or other dust-trapping fabrics.