public boolean hitBy(Bullet b) {
		// Test if alien is hit
		if ((getUpperLeftX() <= b.getUpperLeftX())
				&& (getUpperLeftX() + getWidth() >= b.getUpperLeftX())
				&& (testCollision(b) == true)) {

			ALIENKILLED.playSound();// play the explosion sound
			return true;
		} else
			return false;
	}