Horned Lizards are not the most hardy of Reptiles to keep.
We have had ours for three years now, but it has been trial and error to get the set up and feeding correct.
Ants and Formic Acid are believed to be their main staple diet.
Formic Acid in my opinion and those of some others is not needed in their diet.
Locality is important to their dietry needs, as in Arizona Harverster Ants are in abundance, and small prey too.
Not so in Canada...
Some have a salidic environment, others sandy, some rocky.
I believe some rely on Cactus fluid, and that was noted by my Son who spent 6 weeks in the States.
He spend time watching this Horned Lizard, and its feeding prey...
No Ants.....
For some in Captive Care are housed on Marine Sand, and offered Sea Kelp Powder, which they lick.
Mine also bathe and drink from water bowls... they are offered fresh Cactus Juice and Orange Juice which they relish.
I have noticed they will only go for small crickets, dusted in Nutrobal, and some do not digest Meal or Wax Worms.
UV is essentual, and high day time temps, where at night all heat is removed and light source too.
The plant in the background is fake along with the Cactus too
Julie