Mr. Ochoa: Today we're looking at an animal that a lot of your grandparents probably remember seeing in their backyards: the Texas horned lizard. Some people call it a horny toad, but it isn't a toad at all. It's a lizard, and it's the official state reptile of Texas.

Mr. Ochoa: Its body is flat and wide and covered in spines, with larger horns on the back of its head. Its tan, brown and gray colors help it blend in with dry, sandy ground. When a predator comes close, the lizard's first move is usually to freeze and trust its camouflage.

Mr. Ochoa: If that doesn't work, it has a surprising defense. It can squirt a stream of blood from the corners of its eyes. The blood tastes bad to predators like coyotes and dogs.

Mr. Ochoa: Now here's the part I want you to think about. Most of this lizard's diet is one thing: harvester ants. In many parts of Texas, harvester ants have disappeared, partly because of pesticides and partly because of fire ants, which were brought here from South America and push other ants out. When the ants disappeared, the lizards started disappearing, too. Today the Texas horned lizard is listed as a threatened species in the state, and it's against the law to collect one or keep one as a pet.