Amphibians are in decline in many parts of the world, with stories about plummeting frog populations often making headlines. But for the cane toad – a toxic, invasive species that was introduced to Australia in the 1930s – the picture is a whole lot rosier. Which is nice for the toads, but bad news for just about everyone else. Cane toad populations are skyrocketing, with no known way to control them. What’s more, scientists have now found that the toads are growing longer legs, allowing them to travel farther and more quickly and giving them an evolutionary advantage.

In a study published in the journal Nature, researchers found that the toads, which now cover more than 247 million acres in Australia, can travel up to five times faster than when they first arrived in the country. Native mammals and snakes that try to eat the toxic toads are dying, reported the BBC. One researcher said figuring out how to control the toads is “the $64 million question.”

The toads were introduced to Australia from the Caribbean to control beetle populations. They have no known predators in Australia, outcompete frogs for food, and can lay up to 33,000 eggs per spawning, according to the Frog Decline Reversal Project.

Image credit: Frogwatch