A Bread-like puffball mushroom found in the forest

Today, I went to find mushrooms and slime molds growing around a narrow forest road where decayed wood logs were abandoned.

I found a bread -like puffball mushroom on a forest road soon after walking. 

There are many different types of bread, but in Japan there is a round faintly sweet bread widely sold in a supermarket, and I think it is similar to that.

Having said that, probably it's not sold outside of Japan, so it's hard to imagine what it would look like. This is the bread that I'd like to show you.

Seeing from above, we can see something like broken pieces of mushroom nibbled by insects.  A tiny black dot can be seen on the left mushroom.

This is a tiny beetle.

He's trying to hide his body in the hole he dug on the surface of mushroom.

When I checked later, it was peering out from another hole dug on the mushroom. The holes appear to be connected internally.

By the way, this is a young mushroom.

This is a mature mushroom. (Below photos were taken 2years ago at nearby forest)

When the top surface skin came off with aging, numerous spores appeared.

I think that the spores are entangled with light brown fibrous material.

According to the Wikipedia, its scientific name is Calvatia craniiformis, commonly known as the brain puffball or the skull-shaped puffball, is a species of puffball fungus in the family Agaricaceae. It is found in Asia, Australia, and North America, where it grows on the ground in open woods. Its name, derived from the same Latin root as cranium, alludes to its resemblance to an animal's brain.