Plants can think for themselves (so you don't even need to talk to them). The human race depends on plants or eating things that have eaten plants, but how often do we consider just how astonishing they are? "They live on water and thin air, and they need light, nutrients...and sex. Everyone wants sex," said plant biologist Ottoline Leyser of Cambridge University.
It's easy to assume that plants don't do much, but in fact they are constantly considering their surroundings and their future development, then planning accordingly, for example moving molecules around in response to environmental conditions.
She reminded the Hay audience that "everyone in this room used to be a single cell".
Plants may not have brains, but they do think things through.
Ottoline Leyser is professor of Plant Development and Director of the Sainsbury Laboratory.