If it has eight legs, that makes your creature a spider not an insect. (Or a lobster or crab, but I am assuming you are not speaking of shellfish.)
Beyond that, more detail is needed regarding:
* size of spider (measurement and proportion of body, legs) * location (country/state, and specify basement, flower garden, etc) * behavior (movement, feeding, speed) * web (if any) * markings
None! Your thinking of a spider!
2nd Answer:
The true meaning for bug is a flying insect that has hard wing covers for when it is not flying. A ladybug is an example. All insects have 6 legs, normally.
Ants Earwigs have the pinchers or "cerci" at the back end.
You need to be much more precise. Insects have 6 legs. Spiders and other arachnids have 8 legs. Millipedes and centipedes have many more.
Earwigs have a big orange head with pinchers at the end. They can also have a striped body and six legs.
All insects have six legs. There are many many tiny ones. You need to be more specific.
Pinchers in the back sounds like an earwig.
A cricket is the answer because crickets have grasshopper body and eight legs and its a bug!!!
the lobster-like insect is called a 'pseudoscorpion'
All members of the arachnid family have eight legs each. This includes:SpidersScorpionsTicksMites
Sounds like a house centipede.
By definition, it cannot be an insect if it has eight legs. There are many eight-legged arthropods that resemble insects and spiders. The Harvestman has eight legs but is not a spider. It is part of the mite family. Ticks can be mistaken for insects or spiders, they have eight legs but are in a family of their own.
An ant (insect) fits that description.
It can be a tick: round with short legs or lice, they both have 6 legs.