Scientists who tested lizard intelligence were surprised to find they could learn how to solve novel problems.
The findings challenge the widely-accepted view that reptiles have limited brain power and food-finding strategies.
Biologist Manuel Leal, who led the study of Puerto Rican anoles, a species of green tropical lizard, said the results were “completely unexpected”.
The experiments involved a food-finding test normally used on birds.
Lizards were placed on a wooden block containing two wells, one of which contained a tasty grub and was covered by a tight-fitting blue lid.
Having first learned to recognise the “reward” well from its appearance, four out of six lizards worked out how dislodge the lid.
The findings were published online in the Royal Society journal, Biology Letters.