Hi there,
for an HL as large as you say, 40-80 ants a day should be no problem for it. Granted, you will need to put a few in at a time. No more than ten depending on the size of your enclosure. I would be prepared to feed it 80, but watch how many they average at. I assume you have a Desert Horned Lizard, and thus my advice comes from my own experience with that species. Hope this helps.

-Phil