These layered wool balls are small enough for a cat to pick up with their mouth to carry or toss. They also bat them around and chase them. The layers of wool create a striped pattern which makes the ball more visually enticing as it rolls. Additionally, many cats have a natural attraction to the scent of wool. The balls are now over an inch (2.5 cm) in diameter, larger than before, so they are now packed 4 to a bag instead of 5.