Since then, scientists have continued to study cane toads in hopes of slowing down their invasion. Researchers have documented how some Australian animals have evolved resistance to cane-toad toxin or have learned to avoid the toad altogether. Yet in a recent study, University of Sydney biologist Rick Shine and colleagues found super-fast cane toads are mating with each other, creating fast-hopping offspring and pushing their kind rapidly westward. "The front has accelerated from about 10-15 kilometers per year to about 60 kilometers per year over the time toads have been in Australia," Shine told ABC. "To move at that rate, toads have to behave in very strange ways -- ways that no other frog has before."