Code not working

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

/**
 * Write a description of class Fish here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Fish extends Animals
{
    public int Health;
    /**
     * Act - do whatever the Fish wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        move();
        Respawn();
        Fatality();
    }    
    public void Respawn()
    {
        if(atWorldEdgeforFish())
        {
            //This teleports the fish to either the same spot on the y-axis or a random spot
            //on the y-axis whenever a fish reaches the right edge of the world
            if(Greenfoot.getRandomNumber(3) == 1)
            {
                setLocation(0,getY());
                Health++;
            }
            else
            {
                setLocation(0,Greenfoot.getRandomNumber(getWorld().getHeight() + 1));
                Health++;
            }
        }
    }
    public void Fatality()
    {
        //this will remove fish after a certain number of laps and then add a new fish in
        if(Health >= 7 + Greenfoot.getRandomNumber(4) && Greenfoot.getRandomNumber(21) == 1)
        {
            getWorld().removeObject(this);
            getWorld().addObject(new Fish(), 0, 0);
        }
    }
}