How do you know if your guppy is unhappy?

just wondering

thanks

A healthy fish is an active fish.

Your guppy should be moving about, not settled in on one place or laying on the tank floor. The fish should have a good appetite.

Any fish that shows lethargy or signs of disease or sickness probably isn't going to be healthy or happy.

Make sure the scales are shiny, the eyes are clear, their fins are spread out (not torn or shredded or displaying any signs of rotting), and that their stool is in solid. =]

Normally a guppy will hide under a filter or plants with their tail down. This is a sign of stress.

If your guppy is pale then it is stressed. Also if it is very lazy it isn't doing so well...