Some Animals Give Poison Presents

Wikimedia Commons
Wikimedia Commons / Wikimedia Commons

Characters on Game of Thrones aren't the only ones who hand out poison in the guise of gifts. Some real-world critters also hand out poison as presents, too. Take the Six-Spot Burnet (top), a type of moth, for example. Their bodies are black with a metallic sheen, save for the six crimson spots on their forewings that give them their name and advertise the fact that they’re chock-full of cyanide. The moths sequester the toxic compounds from the plants that they eat as larva and then synthesize the chemicals themselves when they’re older. The chemical defense and warning colors not only keep predators away, but the cyanide also makes a nice gift. 

Researchers in Denmark found that male Burnets with higher cyanide levels were more likely to get to mate with females, and that the males transferred some of their chemicals to their partners during sex. The scientists think that the “nuptial gift” could be a form of paternal care: If a mother moth has cyanide from daddy to spare, she can transfer some to her eggs to defend them. The female might also hang on to the poison and emit it as part of a chemical plume that helps her attract more males later on. 

Apple snail parents also give their offspring a little bit of poison when they come into the world. Their eggs contain two proteins, one of which gives the eggs a bright pink color that serves as a warning and one that’s a powerful neurotoxin that scares off all of the snail’s predators except the fire ant. The toxin is as strange as it is effective: Its structure is unlike anything else in the chemical defenses of animals, and was thought to be restricted to plants and bacteria. What’s more, the neurotoxin is made up of two other proteins that normally play a role in immune defense. Joined together, they protect against much more than disease, though, and show that defenses supposedly confined to one kingdom of life can also pop up in another. 

It’s not just invertebrates that have toxic gifts for their babies. Frogs do it, too. Poison dart frogs don’t make their poison on their own, but get it from the insects they eat and then store it in their skin. When the frogs are just born, they don’t have these chemicals and are pretty defenseless, so mom gives them a little bit of hers. Researchers from the US and Central America reported earlier this year that strawberry poison frogs feed their growing tadpoles with unfertilized eggs, which they load up with toxins from their own reserves. Thanks mom!