else if(canMove()) {
        move();
    }

if (x >= myWorld.getWidth() || y >= myWorld.getHeight()) {
    return false;   // <-- returns here
}
else if (x < 0 || y < 0) {
    return false;    // <-- and here
}
else {
    return true;    // <-- and here!
} 
List obstacles = myWorld.getObjectsAt(x,y,Obstacle.class);

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

import java.util.List;
import java.util.ArrayList;

/**
 * Write a description of class Bug here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Bug extends Actor
{
    private static final int EAST = 0;
    private static final int WEST = 1;
    private static final int NORTH = 2;
    private static final int SOUTH = 3;

    private int direction;
    private int foodEaten;

    public Bug()
    {
        setDirection(NORTH);
    }

    /**
     * Act - do whatever the Bug wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        if (atEnd()){
            removeBug();   
            Greenfoot.stop();

        }
        else if(foundFood()) {
            eatFood();
        }
        else if  (canMove()) {
            processKeys();
            move(); }
        else {
            processKeys();    
        } 
    }

    /**
     * Process keys to handle keyboard input
     */
    private void processKeys()
    {
        if (Greenfoot.isKeyDown("left"))
        {
            setDirection(WEST);
        }
        else if (Greenfoot.isKeyDown("right")) 
        {
            setDirection(EAST);
        }
        else if (Greenfoot.isKeyDown("up"))
        {
            setDirection(NORTH);
        }
        else if (Greenfoot.isKeyDown("down"))
        {
            setDirection(SOUTH);
        }
    }

    /**
     * Sets the direction we're facing.
     */
    public void setDirection(int direction)
    {
        this.direction = direction;
        switch(direction) {
            case SOUTH :
            setRotation(90);
            break;
            case EAST :
            setRotation(0);
            break;
            case NORTH :
            setRotation(270);
            break;
            case WEST :
            setRotation(180);
            break;
            default :
            break;
        }
    }

    /**
     * Test if we can move forward. Return true if we can, false otherwise.
     */
    public boolean canMove()
    {
        World myWorld = getWorld();
        int x = getX();
        int y = getY();
        switch(direction) {
            case SOUTH :
            y++;
            break;
            case EAST :
            x++;
            break;
            case NORTH :
            y--;
            break;
            case WEST :
            x--;
            break;
        }
        // test for outside border
        if (x >= myWorld.getWidth() || y >= myWorld.getHeight()) {
            return false;
        }
        else if (x < 0 || y < 0) {
            return false;
        }
        else{
            return true;
        }
        List obstacles = myWorld.getObjectsAt(x,y,Obstacle.class);
        List bugs = myWorld.getObjectsAt(x,y,Bug.class);
        if(obstacles.isEmpty() && bugs.isEmpty()){
            return true;
        }
        else{
            return false;
        }
    }

    /**
     * Move one cell forward in the current direction.
     */
    public void move()
    {
        if (!canMove()) {
            return;
        }
        switch(direction) {
            case SOUTH :
            setLocation(getX(), getY() + 1);
            break;
            case EAST :
            setLocation(getX() + 1, getY());
            break;
            case NORTH :
            setLocation(getX(), getY() - 1);
            break;
            case WEST :
            setLocation(getX() - 1, getY());
            break;
        }
    }

    /**
     * test if we are in top left cell (home).
     */
    private boolean atEnd()
    {
        int x = getX(); //get current x position of bug
        int y = getY(); //get current y position of bug
        if (x == 0 && y == 0 || x == 59 && y == 39 || foodEaten>5) { //if x and y are equal to 0
            return true;        // return true 
        }
        else {             //otherwuse return false 
            return false;
        }

    }

    /**
     *  foundfood method.
     */
    private boolean foundFood()
    {
        Actor food = getOneObjectAtOffset(0, 0, Food.class);
        if(food != null) {
            return true;
        }
        else {
            return false;
        }
    }

    /**
     *eatfood method.
     */
    private void eatFood()
    {
        Actor food = getOneObjectAtOffset(0, 0, Food.class);
        if(food != null) {
            // eat the leaf...
            getWorld().removeObject(food);
            foodEaten = foodEaten + 1; 
        }
        else if(canMove()) {
            move();
        }
    }

    /**
     * Remove the bug from the world.
     */
    private void removeBug()
    {
        World myWorld = getWorld(); // get the world to remove the bug from 
        myWorld.removeObject(this); // remove the bug (this)
    }
}

        List bugs = myWorld.getObjectsAt(x,y,Bug.class);  
        if(obstacles.isEmpty() && bugs.isEmpty()){  

 List obstacles = myWorld.getObjectsAt(x,y,Obstacle.class);
        if(obstacles.isEmpty()){
            return true;
        }
        else{
            return false;
        }