A kitten will be considered a cat when it's nine months old. I once read that a cat was adolescent from about 10 to about 18 months of age... I guess that means s/he's an adult past 18 months of age.
Ethnically, Mexican Americans are a diverse population including Mexicans of Indigenous ancestry, Mexicans of European ancestry (mostly Spanish), and Mexicans of Middle Eastern stock (mainly Lebanese).
People living in Mexico or who are from there are called Mexicans. Most Mexican people speak Spanish. There are also Mexicans who speak Native American languages, like Nahuatl, Maya, and Zapotec. The capital of Mexico is Mexico City.