Could it be??

[Gypsum]

My male A. borellii has been hanging around the mouth of one of the caves all day, and I've only seen one of the two females swimming around the tank. He occasionally sticks his head into the cave, and then darts out. The cave in question is very dark, and there's a leaf in front of it, so I can't see inside at all. Is that the type of behaviour that suggests one of the girls could be in there with eggs?