One of those moths is this guy, who (in flight, not so much in still images) looks and sounds like a miniature hummingbird: https://en.wikipedia.org/wiki/Hummingbird_hawk-moth
After all, in Europe these butterflies are commonplace, but I've never seen the American bird in my life.
You must have caught it within two or three hours after its arrival.
In the US we have similar hawk moths; the tomato hornworm also looks like a hummingbird when it reaches maturity.
Their moths are important pollinators of some nice native flowers.
I'm in the Eastern US, btw.