The search for AAA batteries

Here is a bit of trivial topic for you: I found out this evening that I need AAA batteries. The context: I bought some toys (will tell you what in another post) for Wolfie for Christmas and he thought he would try the toys tonight. But of course the batteries are not included. And to make matters worse, it needs AAA batteries. I thought I had bought some a few months ago, I either went through them already or I put the spare ones where I cannot find them anymore. Be that as it may, I cannot find AAA batteries in the house. So yeah, it is trivial, but very inconvenient.