A creature is generally any living thing that is not human. So, yes.
Another word for a tiny bug is "insect." More specifically, you could refer to it as a "microbe" or "mite," depending on the context and type of creature you're describing. Additionally, "pest" can also be used to describe small, troublesome bugs.
no a bug is another word for insect.
The creature that has a bug with two tails is a scorpion.
Another word for an underwater creature is a deep sea creature. Deep sea creatures include the cornuta, the giant isopod and the humpback anglerfish.
An Insect
being(s)
creatures of the sea
The creature you are referring to is a firefly, which has a bug with antennae on both the front and back.
Creature, organism
lady bug
idk ... roach or a cockroach or something?
Devil fiend