The erythraeid mite, Balaustium murorum, is a nuisance in urban areas of Japan because of its mass emergence. To know the temporal pattern of the emergence, the numbers of mites at each developmental stage were counted on the surfaces of concrete block walls in Chiba Prefecture. The mites appeared for approximately 90 days from mid-March to mid-June. The peak numbers of larvae, nymphs, and adults were observed in mid-April, late April to early May, and mid-May, respectively. The emergence periods of all three stages were almost identical, at approximately 40 days. Nymphs were observed with larvae or adults, but larvae and adults were not observed together.

The behavior of the smokybrown cockroach, Periplaneta fuliginosa, was investigated using the mark–recapture method using an insect capture box and sticky traps in the veranda and rooms on the sixth floor of a 14-floor apartment house in Minato-ku, Tokyo, from the beginning of July 2017 to early October 2017. As a result of the mark–recapture investigation, 5 of 27 marked individuals were recaptured on the veranda, but no cockroaches were recaptured indoors. On the veranda and in the rooms, 92 and 9 individuals, respectively, were captured using sticky traps. Most of the cockroaches were captured near flowerpots. In contrast, more younger nymphs than older individuals were captured in the rooms.

The smoky brown cockroach, Pelipraneta fuliginosa, was going in and out on a tree cave of Japanese Zelkova, Zelkova serrata in which the Japanese honey bee Apis cerana japonica was nesting. The cockroaches fed on dripping honey from the cave.