Insect collecting Insect collecting has left traces in European cultural history, literature and songs (e.g., Georges Brassens's "La chasse aux papillons" ("The Hunt for Butterflies")). The practice is still widespread in many countries, and is particularly common among Japanese youths. Insects are passively caught using funnels, pitfall traps, bottle traps, malaise traps, flight interception traps and other passive types of insect traps, some of which are baited with small bits of sweet foods (such as honey). Different designs of ultraviolet light traps such as the Robinson trap are also used by entomologists for collecting nocturnal insects (especially moths) during faunistic survey studies.
Comma category functors out of the product category formula_97. For each comma category there are forgetful functors from it. Several interesting categories have a natural definition in terms of comma categories. Limits and colimits in comma categories may be "inherited". If formula_1 and formula_2 are complete, formula_145 is a continuous, and formula_146 is another functor (not necessarily continuous), then the comma category formula_6 produced is complete , and the projection functors formula_148 and formula_149 are continuous. Similarly, if formula_1 and formula_2 are cocomplete, and formula_152 is cocontinuous, then formula_6 is cocomplete, and the projection functors are cocontinuous. For example, note that in