Based on your avatar pic, I'd say they like what they see.
When I find a woman staring, I look them directly in the eyes and smile. If it was an innocent stare of appreciation, the smile is an acknowledgement. If the stare was intended to be hostile, they will wonder what I am smiling about: maybe they have ketchup on their nose? I reject their hostility and then go about my life.
If it is a man staring, I don't make eye contact or acknowledge their existence in any way. Just not worth it.