113 days to go to Insect Week
The Centre for Ecology & Hydrology is the UK’s centre of excellence for integrated research on terrestrial and freshwater ecosystems and their interaction with the atmosphere. As a Centre of the Natural Environment Research Council, it provides innovative, independent and interdisciplinary scientific studies and long-term environmental monitoring (including the work of the Biological Records Centre).
There are lots of contenders here – possibly the pretty red and blue rove beetle Paederus – very, very tiny amounts of its poison have been used to cure chronic ulceration in people. Ladybirds are pretty poisonous (and pretty) and can bleed foul-tasting poisonous brightly coloured blood from their knees.