Pitchers plants are carnivorous. They catch small animals, usually insects to gain nutrients like Nitrogen. You’d expect that they’d evolve their traps to be as effective as possible. If an insect gets away, that’s one less meal, but that’s not what happens for Nepenthes rafflesiana

N. rafflesiana is a plant that grows in sunny parts of the forests of Borneo, Sumatra, and the Malaysian peninsular. It grows a couple of traps, though the upper traps lack the waxy crystals of the lower traps. Both traps have a peristome, a lip that is very slippery when it’s wet to encourage insects to fall in. But often is isn’t wet. In fact the change in humidity through the day means that it can be dry for eight hours or more. Dr Ulrike Bauer from Bristol decided to have a closer look at what was going on.