Only the makes bark to my best research. But their is a big question I have how often are you using frozen mice? If its more then every 5 weeks be very careful their extremely high in fat and can do kidney damage. In stead of red wigglers I recommended other grubs rw's can rob the frogs of trace minerals not bad as a treat but as a staple calciworms(soldier fly larvae sold at petco) waxworms, and crickets that are gut loaded would be a better safe bet. Other then those few concerns I think the pixie frog is reaching a young maturity level unless maybe you got a dwarf pixie which maxes out in males around 4.5" and is coming into barking due to proper conditioning.