Keeping horned lizards is difficult because most are ant eaters. Phrynosoma asio apparently eats other insects as well.
Question: Does anyone breed horned lizards? How big do the largest types get?
Jonathan Alcorn, Terra Haute, Ind.
Unusual for a horned lizard, the diet of Phrynosoma asio is not limited to ants.
Answer: Keeping and breeding horned lizards of the genus Phrynosoma has lagged behind that of most other iguanid lizards so far. This is partially because many “horned toad” species are specialists that eat only ants — a difficult diet for most hobbyists to provide, leading them to avoid working with horned lizards for that reason. It hasn’t been until the last decade or so that a species has emerged to help dispel that stigma: the giant horned lizard Phrynosoma asio.
This “new” arrival into the herpetocultural arena is native to the southeastern extreme of Mexico and adjacent Guatemala, but is now being bred in small numbers. The species grows to about 6 inches in length, and the big plus about it is it does not restrict its diet to only ants. It will be interesting to see if it becomes more widespread in the hobby over the coming years.