 They sequenced the pollen that they had on them to like prove, yes, these butterflies had recently been in West Europe and West Africa. There wasn't just like some random person decided to have a bunch of pet painted lady butterflies over on the other side of the planet. And then they started looking at wind patterns that might have helped them. And they think that the Saharan air layer, this air current that we already know does really amazing stuff. It blows dust from the Sahara over to South America and