We have lived in two different houses here in Mississippi, neither of which have had carpet.
Since there is so much mud and dirt, carpet could actually be a nuisance. Considering that I sweep at least twice a day, depending on our outside adventures, I'm glad to not have mud-stained carpet.
So, I know it's time to sweep when my family members start to do ballet moves to remove the dirt specks from the bottom of their feet!
Imagine, if you will, running the bottom of your right foot on the inside portion of your left shin. I think it's ballet position number 3, though it's been 30+ years since I took that class!