Thinking on your feet - Brain Size

Smithsonian researchers report that the brains of tiny spiders are so large that they fill their body cavities and overflow into their legs. 

As part of ongoing research to understand how miniaturization affects brain size and behaviour, researchers measured the central nervous systems of nine species of spiders, from rainforest giants to spiders smaller than the head of a pin.

As the spiders get smaller, their brains get proportionally bigger, filling up more and more of their body cavities.

A whole new meaning for thinking on your feet