Biscuit and the quails

I allowed Biscuit to explain things:

Well I came into the garden. Wandered around as normal. Thought I would check the quails. Nothing new there. I always visit them when I'm around. We've had our problems in the past but that's all sorted. They know me. I know them. No problem.

I saw their pen. Bit empty. They must be in their house. Bit strange. Still I checked out the pig sty. Back to the pen. Hole in fence. Quails gone.

I layed down by their pen. They are my friends and they've gone missing. That's not nice.