When animals invade without the "help" of humans, it happens in a very different speed which the ecosystem can adapt to.
And even tho I made the joke, I wouldn't say humans are the problem. Humans lived more or less "in harmony" with nature and then came colonialism and capitalism. Humans are capable of living differently, the market is not.
Damn that's crazy, we hear about the feral cats being super bad for the native species but not red foxes, they're pretty rare here in the US, or at least in my area.
I heard some libs doing a sinophobia at all the DISGUSTING CHINESE CARP ruining the great lakes, as if Xi himself trained a flotilla of carp to destroy lake michigan