I had one of these a year or two ago.
Ours lived normal lifespans, but since ants have age-based roles that change as they mature from nursing/digging to foraging to defending they only really remain active for the digging phase and sit around for a month or two before they die.

as a canadian I can vouch for the fact that we aren't really all that metric.
Ask a canadian how tall they are in cm or how much they weigh in kg and their inability to answer will show you that we never completely gave up imperial.

ottawa and toronto have them too, ottawa's is small but pretty fun, and ends on parliament hill

fantasic!! your cat is awesome.