General

• Bug ID - Identify unknown insects by answering a series of questions. 
• Bug of the Month - Pictures and information about an insect for each month of the year. 
• eNature Field Guide: Insects and Spiders - Browse by type of insect, or use the advanced search to look for color, size, region, habitat and more. 
• Entomology For Beginners - An introduction to the study of insects. 
• Insect Information Sheets - Provides facts about fourteen different kinds of insects. 
• Insect Printouts - Insect graphics and blank diagrams to print out and use.
• MicroAngela's - Electron microscope (very close up) images of bugs and other cool stuff.

Ants

• Gakken's Photo Encyclopedia of Ants

Butterflies

• Butterfly Wing Patterns 
• Family Butterfly Book activity kit

Spiders

• Arachnids! 
• Minax Tarantulas
• Spiders - Brief overview of spiders in general, specific information about several North American Spiders

Worms

• The Adventures of Herman