I received this from the workers who were cutting down trees in a nearby park. It was split like in the photo. I think it's a Japanese woodpecker's nest. It seems to have split during the tree felling. I'd never seen one up close before, so I thought it was interesting and took it. If anyone is interested and would like to take a look, please do. Feel free to comment if you have any questions. Thank you. I don't have a suitable box, so I'll make one from recycled cardboard when I send it.