Top 10 Arthropods that are Mistakenly Called Insects

For those who don't know what an arthropod is, it's an invertebrate animal of the large phylum Arthropoda, such as an insect, arachnid, or crustacean.

There's a lot of arthropods who get easily mistaken for insects. And I've got a list of ten arthropods who get called insects, but aren't insects.
The Top Ten
1 Spider

People call them bugs all the time. Well guess what? They're not bugs! They're arachnids.

2 Scorpion

Scorpions are also arachnids.

3 Isopod

Isopods are crustaceans.

4 Water Flea

Despite the name, water fleas are crustaceans.

This doesn't look like an insect to me...

5 Trilobite

This extinct creature is not an insect, but belongs to its own class called Trilobita.

6 Copepod

Copepods (and other species of plankton) are crustaceans.

7 Centipede Centipedes are arthropods belonging to the class Chilopoda of the subphylum Myriapoda. They are mainly carnivorous and they prey upon insects, spiders, small birds and rodents, and even other centipedes.

Same with millipedes. They're not insects because they don't have three legs.

Cross between centipede and millipede!

8 Millipede Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name being derived from this feature.

Millipedes can't be insects because insects only have three legs while millipedes have more than three.

9 Daddy Longleg
10 Woodlouse

Despite the name, they're not lice. They're crustaceans.

The Contenders
11 Tick
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