What age will you stop menstruating?

There is no real age for teething. Obviously when the child has their teeth, that's when they stop. Some kids are born with teeth, and some don't get teeth until there a year old. SO it really...

Humans stop around age 18-21.

it is your choice but i advice you that if you are aboutt 70 years old DO NOT ride because it might strain your bones. p.s. always wear a safety helmet whilst riding.

You are normally fully developed and sexually matured by the age of 21.

I would say about at year 1. My shorkie is about a year and 1/2 and he is pretty much full grown.