German cockroaches favor warm, humid spaces near food and water — kitchens, behind appliances, under sinks — and Colmar's a humid climate with hot summers and enough elevation-driven snow to matter every winter keeps them active most of the year. American cockroaches, larger and reddish-brown, prefer basements, drains, and utility rooms. A mix of historic mill and mining-town housing and newer development tied to the region's logistics and warehouse growth.
We start with an inspection to identify the species and the source — sanitation issue, moisture problem, or entry point. Treatment centers on gel bait placed in cracks, voids, and under appliances, not broadcast spraying, since German cockroaches in particular have developed resistance to many surface sprays. A follow-up visit confirms the bait is working and the population is dropping.