They are often active at night, sometimes waking owners with loud meows.
They may become less interested in cuddling, preferring to explore or spend time alone.
What happens to cats during puberty? | Blog - Cats Protection
Kittens grow into long, lanky "teenagers" with disproportionately large paws and limbs before filling out.
Around 1 year, it is often recommended to switch from high-calorie kitten food to adult food to prevent obesity. Tips for Surviving the Teenage Phase