I think there’s a solid argument to be made for ants as the world’s dominant species. There are even supercolonies that span multiple continents. https://pmc.ncbi.nlm.nih.gov/articles/PMC3352483/
They will likely continue to thrive in the post-human global environment. Their success does not rely on human development (like, say, rats), nor are they severely threatened by human development (like…well, most things).
Fun fact: octopuses* respond to MDMA, and become social and cuddly. https://www.pbs.org/newshour/science/scientists-gave-octopuses-some-molly-heres-what-happened
I seem to recall a similar story where drug exposure reversed the octopus’s usual behavior of simply waiting for death after mating, but I couldn’t find a reference from a quick search so perhaps I am misremembering this story, about the biological mechanisms behind that behavior: https://www.sciencealert.com/scientists-close-in-on-why-octopuses-tragically-destroy-themselves-after-mating