How to move multiple images randomly using java swing

I am trying to randomly move multiple images in jframe.They should move randomly all over the window . I can do it only for a single images.But when i am trying to do that multiple images , i can't.Here is the code for moving one image randomly. Please give me some idea what i should do to work the code for multiple images

package javaapplication13;

import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.ImageIcon;

import java.awt.Image;
import java.awt.Graphics;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

class animate extends JPanel implements Runnable
{
    Image img;
    int x=100,y=100,d=10;
    double angle=0;
    int width,height;
    int DELAY=10;
    animate(int a,int b,String str)
    {
        width=a;height=b;
        ImageIcon ii = new ImageIcon(str);
        img=ii.getImage();
        new Thread(this).start();
    }
    @Override
    public void run() {
        long beforeTime, timeDiff, sleep;
        beforeTime = System.currentTimeMillis();
        int cnt=0;
        while(true)
        {
            if (cnt>30)
            {
                cnt=0;
                angle=(Math.random()*360)%360;
            }

            cnt++;
            x+=Math.cos(angle)*d;
            y+=Math.sin(angle)*d;

            if (x>width)
            {
                x=width;
                angle=(Math.random()*360)%360;
            }
            else if (y>height)
            {
                y=height;
                angle=(Math.random()*360)%360;
            }
            if (x<0)
            {
                x=0;
                angle=(Math.random()*360)%360;
            }
            if (y<0) 
            {
                y=0;
                angle=(Math.random()*360)%360;
            }
            repaint();
             timeDiff = System.currentTimeMillis() - beforeTime;
              sleep = DELAY - timeDiff;

            if (sleep < 0) {
                sleep = 2;
            }

            try {
                Thread.sleep(sleep);
            } catch (InterruptedException e) {
                System.out.println("Interrupted: " + e.getMessage());
            }

            beforeTime = System.currentTimeMillis();

        }
    }

    public void paint(Graphics g)
   {
       super.paintComponent(g);
    g.drawImage(img,x,y,null);
   }

}
public class DrawImageOnJFrame extends JFrame 
{
    public DrawImageOnJFrame()
    {
    //set JFrame title
    super("Draw Image On JFrame");

    //Get image. You must change image location follow to image location in your computer.

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(700,700);
    setResizable(false);
    setVisible(true);
    add(new animate(700,700,"fish.png"));
    add(new animate(700,700,"cat.jpg"));
   }



   public static void main(String[]args)
   {
       EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    try {
                        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                    } catch (UnsupportedLookAndFeelException ex) {
                        Logger.getLogger(animation.class.getName()).log(Level.SEVERE, null, ex);
                    }
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException ex) {
                }
                     DrawImageOnJFrame diojf=new DrawImageOnJFrame();

            }

        });

   }
}