It was 2:30 p.m. on a Wednesday, and Reid Matsuda was looking for rat burrows. Matsuda, a program supervisor for the city of Denver’s residential health and housing investigation team, was visiting the Mosiac Apartments, 6900 E. Evans Ave., on that recent afternoon for a follow-up inspection. The complex had made headlines in 2023 after repeated complaints about rats and other problems generated an all-hands-on-deck “proactive” inspection from city investigators. Repeated visits eventually resulted in thousands of dollars in city fines against the property’s management. “We really had to shake the tree and get them on board,” Matsuda said.