Exploding acorns.

I didn't know what these were but it seems they're knopper galls, which are caused by gall wasps laying eggs in the buds. Not a very photogenic subject, but even ugly things deserve a chance to appear on tiny tuesday, I say!
Many thanks to Nickimags888 for hosting.
The extra is a buzzy thing (apologies for not knowing if this is a variety of bee or hoverfly!) which I like because of its wings.