Adaptive camouflage: what can be learned from the wetting behaviour of the tropical flat bugs and .

The neotropical flat bug species and show a fascinating camouflage principle, as their appearance renders the animal hardly visible on the bark of trees. However, when getting wet due to rain, bark changes its colour and gets darker. In order to keep the camouflage effect, it seems that some species benefit from their ability to hold a water film on their cuticle and therefore change their optical properties when also wetted by water.