Paradise: Ants On Iris At Hidden Villa. Winter Ants (Prenolepis imparis) on the stem of a white Iris. The Horned Toad Lizard (see below) thrives on native ants such as Prenolepis -- and especially on Harvester Ants -- but the exotic invasive Argentine Ants are much less nutritious. Luckily for the Horned Toad Lizard, there is evidence that the spread of Argentine Ants is limited to settled areas and nearby, mostly. Us seeing this Prenolepis at Hidden Villa gives hope to the Horned Toad Lizard.