I thought I had just moved in and kept it clean, but I ran into a cockroach in the room ... I've experienced it, but when I'm completely relieved, I'm quite shocked.
Even if there is no nest indoors, they are troublesome to invade from all gaps such as drains and windows. One of the routes is said to be the drain hose of a dark and humid air conditioner.
The "insect repellent cap for air conditioner drain hose" sold at the 100 yen shop "Ceria" is a cap that can prevent insects from invading the room just by inserting it into the drain hose. It corresponds to the size of hose inner diameter 1.4 cm and 1.6 cm, and if the inner diameter does not match, cut the hose and attach it.
The tip of the cap has a net-like structure that allows large insects to pass through while draining water. It is necessary to check regularly for dirt and dust, but for the time being, this seems to be a relief.
By the way, there are cases where a cap is attached when installing the air conditioner, so in that case it is better to suspect another intrusion route. Before the temperature rises and the insects become active, why not take measures with Hundred yen store goods?