Why is my fish doing this?

Question

Why do my 3 mollies and 1 female gourami nibble my finger when I stick the tip of my finger into the water?

Answer 1

They know you as the hands that feeds, mistakes it for food.

Answer 2

Taste testing! Cute, they may like the salt from your finger...I'm not too sure why they would do that, but it is cool that they intereact with you in that way.

Answer 3

I think they think you are gonna feed them and your finger is food! I have a few rainbow fish do that to me, really cute!^^

Answer 4

Yeah my Zebra Danios go for my finger every time it touches the water and even the plastic tube when I'm testing the water. It's normal, all healthy fish should act like they're constantly starving.