Robot

import java.awt.AWTException;
import java.awt.Robot;
import java.awt.*;

Robot robot;
 
void setup() {
	size(600, 600);

	try { 
		robot = new Robot();
	} 
	catch (Exception e) {
		e.printStackTrace();
	}
}
 
void draw() {
	background(255);
	
	Point p = getScreenLocation();
	int px = (int)p.getX();
	int py = (int)p.getY();

	int mx = int(px + random(-20, 20));
	int my = int(py + random(-20, 20));

	robot.mouseMove(mx, my);

	ellipse(mouseX, mouseY, 20, 20);
}

Point getScreenLocation() {
	PointerInfo info = MouseInfo.getPointerInfo();
	Point p = info.getLocation();
	return p;  
}