In the immediate sense, it made Tony's longshot proposal even more tenuous, because if the rest of the animals weren't around, it stood to reason that the rock animal had vacated as well. More broadly, if the local animals were overtaken, or abandoned the area as uninhabitable, that didn't bode well for a few scrappy aliens. "It's like an invasive species. No natural predators," he said. Except, outside of some flare and extra energy, Tony was pretty sure these plants had been here all along; he and the other he rows were the invaders, maybe they had to start thinking like it. "We have to start making more babies," Tony muttered.