Thanks for the replies, and sorry about the clarity i was half asleep.
What i need to do is find a way for an enemy to not fall off the screen when physics is enabled. However, i am unable to create any sort of static floor. Instead, what i have done, is create a rectangle object and tell it to follow Enemy position.
I imagine having 30 different rectangle objects, set to a position every tick, and telling them not to collide with each other probably isn't the best way to go about doing it.
An alternative would be to have it so the enemies only have force applied on the X axis, No idea how to go about doing that, I couldn't find much info on the physics.