Whether its just for fun or training, the bright colours make them easier to find than your average tennis ball if your puppy is one for abandoning the ball in the middle of the filed.Solid - bite resistantNon-toxic substance** Pets should be supervised whilst playing with toys. Although Petface toys have been designed to be strong they are not indestructible and will be susceptible to chew damage. The life of a Petface toy depends on the ability and strength of your pet. Monitor for wear and replace if damaged.**