Squids spawning everywhere.

Squids seem to spawn at the most improbable places as of lately. I had a small 2x2 pool (1 block deep) as an infinite water source, and there had been squids spawning in it for the second time now (2-3 squids). I think letting them spawn in such a small area is going a bit too far, they should more or less spawn in the deeper water zones.