Jan Hamrsky: Darner dragonfly nymph (Aeshnidae) which is bright coloured and clean because it has just shed its old skin in order to grow larger. The new skin gardens and gets darker in few hours.
Jan Hamrsky: Diving beetle (Platambus maculatus). Beetles often expose a bubble of air in order to gather molecules of oxygen from the surrounding water. Their air store must be refilled time to time, nevertheless this behavior increases the capacity of stored oxygen.
Jan Hamrsky: Case-building caddisfly larva (Arthripsodes cinereus) crawling at the bottom in its protective case made of sand grains.