Ohhh. Well the big parts that grab stuff are mandibles. They aren't legs but they originate, evolutinarily speaking, from legs. Same with antennae! The parts closer to the head do the eating but sometimes mandibles help with that.
For venomous arthropods sometimes it's the mandibles that have the venom (like spiders, where they are called Chelicerae), for some it's saliva and they use various mouthparts (the water bug uses a proboscus), for some it's their tail end (like ants), etc etc.
Can they actually bite using those things or are there just there to look scary?
The lower left is a toe biter water bug with one of the most painful venoms on the planet
I'm getting very mixed answers here (someone else said that's it's legs
Ohhh. Well the big parts that grab stuff are mandibles. They aren't legs but they originate, evolutinarily speaking, from legs. Same with antennae! The parts closer to the head do the eating but sometimes mandibles help with that.
For venomous arthropods sometimes it's the mandibles that have the venom (like spiders, where they are called Chelicerae), for some it's saliva and they use various mouthparts (the water bug uses a proboscus), for some it's their tail end (like ants), etc etc.