a butterfly net (sometimes called an aerial insect net) is one of several kinds of nets used to collect insects, not just butterflies. the entire bag of the net is often made from a lightweight mesh (or web of threads) for less damage to thin butterfly wings. other forms of nets used in insect collecting (for entomology) include: beat nets, fishing nets, and sweep nets. nets for catching different insects have different mesh sizes, with less space between the threads. fishing nets usually have bigger, more 'open' mesh. catching small aquatic creatures usually requires an insect net. the mesh is smaller and can capture more forms of animals.