Why did my bearded dragon eat the other dragon's toes?

If you didnt already know, most dragons use there eye sight to see there prey when they are hunting... Usually when more then one dragon is keep in the same enclosure, a hard subtrate is recommended.. when a dragon is on, say, walnut shells, there feet tend to hide underneath the substrate. So when they move around there feet/toes may sometimes look like food to another dragon.... If you are housing more than one dragon together, I would recommend using something hard.. Things I would use are pieces of tile, reptile liner or even alfalfa pellets.... Ifyou are only housing one dragon, you are pretty much ok with anything.... With my dragon, I have her on alfalfa pellets. She seems to like them very much.. Plus another advantage I have found with alfalfa pellets is that it make your room smell pretty good.. I have her in a 60 gallon tank so it requires a 25 lb bag of pellets......