Age? It's important information since chick development is lightening fast.
Very young chicks occasionally get fixated on some small detail and then they obsess. The solution is a harmless diversion. In other words, give the chick something else to focus on.
Have you by any chance given your chicks meal worms? This often leads an obsessive chick to notice that chick toes resemble worms. So give the chicks something that resembles chick toes to divert their attention.
In coming up with a substitute for chick toes, try to think what would be harmless but still provide an interesting plaything. How about cooked spaghetti? Cut the strands into two inch lengths and place them randomly around the floor of the brooder.
Recently, my present chicks were fixated on chick vents. It resulted in a couple of bloody injuries, and I came up with a tennis ball with red magic marker dots on it, and a small block of wood with a foam weather stripping noodle stapled to it that was decorated with red duct tape.
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Whatever you come up with, be sure it's soft so it won't harm delicate baby beaks.