Why do all paid fire departments in Cape May County respond to

Cape May County - Why do all paid fire departments in Cape May County respond to calls outside of their own jurisdiction with out being requested? Hope they are not needed on the island. And when they are requested they can’t come anyway, because of man power issues. Seems like they only show when they can be the big hero’s. It’s not mutual aid,it’s freelancing. If this was the other way around with the volunteers jumping the paid guys calls ,it would be a big deal.