Not silly at all. Yellow labs are mouth-brooders which means that after the eggs are fertilized, the scoop them up in their mouth and keep them there for 3-4 weeks to incubate them. The eggs then hatch in the female's mouth and she eventually lets them out. The "holding" period is the time when they are incubating in her mouth. This time is dangerous to a female because she doesn't eat for 3-4 weeks and can be constantly harassed by males. My second one did a good thing in hiding in the rock work (this is what they are supposed to do), but my other female is not experienced and she was just hanging out. She was getting beat up pretty bad because of this. That is why it is good to seclude them in a breeding tank during this period. It also ensures that the fry don't get eaten (unless mama decides to - again from inexperience) and it gives you a chance to get the female back in full health before adding her back to the tank (usually give her 1-2 weeks in the breeding tank after the fry have left her mouth so she can get back to full health, start eating again, etc.). Feel free to ask any further questions you have.

very interesting - -thanks for the breeding lesson

yeah... try to take them out... i'll look for a video of some dude doing it to some frontosas...