What do you do if your head ain’t big enough for your brains? Answer: stuff it down your trousers!

Well, at least that’s sort of what the tiny Anapisona simoni spider has to do. These spiders are miniscule and weigh only 5 micrograms, but are just as clever as any other spider when it comes to weaving webs.

William Eberhard of the Smithsonian tropical research Institute in Panama and the University of Costa Rica, along with colleagues, has observed the consequence on the brain of this little spider’s ability to weave complex web patterns. It turns out that their thinking matter spills out of their heads, and into 80% of their thorax and even into their legs!

It makes you wonder how there could be enough space in their body for all the other necessary organs, such as their digestive system, for a start.

You’d think this insect was a one-off, but the Anapisona simoni spider, is not the only brainy creature built this way. Many tiny insects’ brains go beyond their heads and into their abdomens, and salamanders have evolved with fewer bones in their skulls to make room for their brains.

And even though we know that the more you use your brain, the more white matter you create, and the bigger your brain gets, I don’t know about you, but I rather suspect it won’t be necessary for my brain to find extra space.

I’m afraid I already have more brain than I’m using!