Cockroaches like to live in storm drains and sewers. Most houses are on sewer lines.

I worked on a maintenance crew for a school. Although the school was quite clean, the school had the problem that whenever there was a heavy rain, the cockroaches would swarm out of the storm drains.

The cockroaches were slippery and they would cause accidents when people hit the swarm of cockroaches.

So, imagine hitting a swarm of cockroaches, swerving and hitting a telephone pole. When you step out of the car, the swarm of cockroaches would then swarm over your shoes.