The main exhibition topic in the Arena Glasshouse is a variety of carnivorous plants, mainly Pitcher plants. The glasshouse simulates a tropical rainforest environment – which is warm and humid, which is optimum for pitcher plants. The soil is too poor in a natural rainforest environment; therefore,Pitcher plants catch insects in order to obtain their mineral nutrition – Nitrogen. Therefore, various ways on catching insect is an amazing revolution of phylogeny on the same purpose.