We can choose to reincarnate into whatever living; plant, animal or being we want. If we choose, we can reincarnate into a different world or ” alien” species if we like as well. It all depends upon our learning goals for that particular life. Most often souls reincarnate back into physical human form on Earth mainly because humans are more complex creature’s vs lower life forms such as; dogs, insects, plants, etc. However, if there is a specific lesson(s) that can ONLY be learned as a lower life form then yes, it’s possible.
Cant wait to see who you’ll be in your next life!
Love & Light!