ArachKnowledge

Interested in learning about arachnids?
A simple dichotomous key to common arachnids.
Are you looking for activities and lessons about Arachnids for teaching?

About Arachnids (many links are to Wikipedia pages on arachnids)

Arachnids are a class of arthropods (animals with jointed appendages) that have eight legs. Other arthropods are insects, crustaceans (like crabs and lobsters), and myriapods (centipedes and millipedes.

There are 11 living and 3 extinct orders of arachnids

Acari - mites and ticks
Amblypygi - tailess whipscorpions/cave spiders
Araneae - spiders
Haptopoda (extinct)
Opiliones - daddylonglegs/harvestman
Palpigradi - microwhip scorpions
Phalangiotarbida (extinct)
Pseudoscorpions
Ricinulei
Schizomida
Scorpions
Solifugae- camel spiders/sun spiders/wind scorpions
Thelyphonida (formerly Uropygidae) - vinegarroons/whip scorpions
Trigonotarbida (extinct)

**Simple key to common arachnid orders**

There are 8 jointed walking appendages (legs)

1.a There is a tail .......... go to 2
1.b. There is no tail .......... go to 3

2.a. The tail is slender and needle-like .......... Thelyphonid - vinegarroons/whip scorpions
2.b. The tail is broad and has a stinger .......... Scorpion

3.a. There are a pair of scorpion-like claws .......... go to 4
3.b. There are no scorpion-like claws .......... go to 5

4.a. It is less than 5 mm (1/4") long and dorsoventrally (top to bottom) flattened .......... Pseudoscorpion
4.b. It is 8 to 50 mm (1/3" to 2") long .......... Amblypygid - tailess whip scorpion

5.a. There appears to be one body part and no "waist" .......... go to 6
5.b. There appears to be two body parts and a distinct "waist" .......... go to 7

6.a. Legs are very long and slender compared to the body .......... Opilionid - daddy longlegs/harvestman
6.b. Legs are short compared to the body .......... Acarid - mite or tick

7.a. First pair of legs is much longer than the rest .......... Solifugid - camel spider
7.b. First pair of legs is not much longer than the rest .......... Araneid - spider

Activities and Lessons

Books (Children) links are to Amazon

Type - F (fiction), NF (non-fiction)
Age Bands - PreK (0 to 4 years), EE (K to 2nd, 5 to 7), UE (3rd to 4th, 8 to 10), MS (5th to 7th, 11 to 13), J/HS (8th to 12th, 14 to 18)

The Very Busy Spider by Eric Carle - PreK, poetical introduction to the role of spiders
Be Nice to Spiders by Margaret Bloy Graham - F, PreK to EE, how spiders help the animals at the zoo by keeping flies down
National Geographic Readers: Spiders by Laura Marsh - NF, EE to MS
Are you a Spider (Backyard Books) by Tudor Humphries - F, EE, biology of spiders
Charlotte's Web by E.B. White - F, UE to J/HS, classic in children's literature, fantastic elements (talking animals), coming of age, adult themes (death of Charlotte, the spider, sacrifice for others) but affirming ending.
Children's Guide to Insects and Spiders by Jinny Johnson - NF, PreK (the pictures) to MS

Books (Youth - 8th to 12th & Adult)

Spiders and their Kin (Golden Guide) by Herbert W. Levi, Lorna R. Levi, Nicholas Strevolasky (ill.) - NF

Movies

Charlotte's Web - based on the book by E.B. White, Dakota Fanning, Charlotte voiced by Julia Roberts

Lessons (for classroom use)

Resources A to Z Lessons on Spiders

Activities (for outreach or informal educational use)