Identifying insects usually proves more difficult than identifying other organisms for a number of reasons.

1) There are an enormous number of insect species (well over 1 million described insects and related arthropods). Many entomologists estimate another several million more exist.

2) Insects are small; most insects are 6mm or less in size and the identifying characters are difficult to see. It may be necessary to use microscopes or other means of magnification to observe them.