Hitched rides from on European ships.the Black Tat is the first invasion species to ever be inadvertently distributed by humans.
It's success as a species, in combination with the success of numerous other species of rats, is believed to have come at the expense of dramatic population declines and excitation of countless other Animals reptiles, birds etc.
They spread thru things like international tire trade, inside the tire was rain water so that gave them a chance to breed and living conditions.
It carries viruses and this is a huge impact on ant different places in the world, it tends to associate with humans the most and they feed 24hrs a day.