I've seen a few cockroaches in our bathroom and bedroom, but nowhere else in the house. There is a bad, though not overwhelming, smell in our bedroom that comes and goes every few days and lasts for several hours each time it comes. It smells sour, wet, and somewhat like garbage. It definitely doesn't smell like a dead animal. I've sniffed around everywhere and can't figure out where exactly it's coming from. I keep the house very clean. There's no rotting food, garbage, or clutter in the bedroom. I've heard that a bad cockroach infestation will cause a smell. What does this smell like? Also, is it constant, permeating the entire home, or does it come and go in a single location as I've described? What else could this smell be if not cockroaches?

For every one you see, there are probibly 100 that you don't.

You need an exterminator if you see that many.

A cockroach infestation can generate an odor most often described as "coppery." The odor you describe makes me think of mildew/fungus. Is there a wet spot such as from an air conditioner drain near a window? In the crawlspace?

It sounds like you have two separate problems.

The roach problem can best be addressed by gel baits. A professional exterminator should offer a one time application, perhaps with a follow-up warranty, for a reasonable price. If you want to do it yourself, be careful not to apply too much in any one place. A hundred little placements is much more effective than 10 larger ones where you saw the bugs.

The sour wet odor can be best addressed by inspecting for damp spaces inside, outside, and under the house.

Roaches are almost impossible to elimate on your own. And it is stages, since they lay eggs, and hatch.. a professional is needed if it is a reoccuring issue