Fish help please

We wanted to create a School of Fish and have them swim in random directions, Hes got his fish in the water and he has them built into a list so they will all move at the same time but we cant seem to get it to be random moves no matter how we program it. And when we thought we had them swimming randomly we couldnt keep them onscreen?

Fishy69's Code
Created by: Cath
world
Events
When the world starts
Do: world.my first method




Methods
world.my first method ( )
Fish Family =
Loop index from 0 up to (but not including) infinity times incrementing by 1
For all Fish Family , every item_from_Fish Family together
item_from_Fish Family move forward 1 meter
For all Fish Family , every item_from_Fish Family together
item_from_Fish Family turn right 0.25 revolutions


Its not random and it doesnt account for the fish going off screen

well, to tell you the truth there is no easy way to make it so that everything stays onscreen as everything moves away randomly. but it is doable. my suggestion is to just have them move randomly within an area