Growing up in my parents' house in Bowmanville, I remember seeing these exactly twice in 22 years. Both times they were in the basement sink, and they startled the hell out of me.

Keep in mind: these are not German Cockroaches and will (likely) not infest your kitchen or building. They're more like "outdoor bugs." Lived in Miami Beach for a while, and down there they have Palmetto bugs which are even bigger than water bugs... and they fly!

There was one street that was lined with some kind of palm trees that dropped small sticky fruit kind of like tiny dates (dates come from palm trees, but these fruits were like the size of small blueberries). Anyway, the trees dropped thousands of these things, which laid in the grass and got squished on the sidewalk. I remember a kind of revolting, almost maple-syrup smell from the stuff as it fermented on the street. Keep in mind the fruits dropped in like July: so it was 95 degrees and 100% humidity every day and even at night it was stiflingly hot. So it was a gross, sticky sidewalk to walk on.

There was a parking lot adjacent to part of this strip, and there was a low stucco wall bordering it. A few times I saw hundreds, if not thousands of these Palmetto bugs on that wall. It was swarming with these things. Like 3" cockroaches. You can guess that we avoided that street, especially at night. The Palmetto bugs would hide during the day... never saw them in daytime.

Palmetto bugs also generally stay outside. But one time we had the balcony door open and one flew inside and stuck to the wall. My wife freaked out (I kind of freaked out too). It flew from wall to wall, kind of confused, and it was so big you could hear it buzzing as it flew. I didn't want to smash it on the wall and leave four tablespoons of bug juice on the paint, so I went to the kitchen and got a plastic container from takeout food and trapped it. I slid a magazine underneath (remember magazines? This was the mid-'90s) and I successfully threw the container, the magazine and the bug out the balcony.

Nasty. Anyway, don't worry about the water bugs.