Homecoming Queen,
When a fish wallows out a hollow in a shallow shoreline and lays eggs in it, it's called a "bed".
Hence, the bass, bream, or whatever are "bedding" or "on the bed".
Some fish, like shad, herring, and salmon, simply lay the eggs on the stream "bed", the males ferment them, and on they go.
Those eggs hatch sometimes a long way from where they are "laid".
All this talk about "beds" and "laid" making you horny?
Really,
Just Kidding.
Have fun,
Phil
Edit: Not kidding about the fish.