Namaskar,
In my opinion, “souls” do not “live in” but “manifest through”. It is the same universal god-consciousness who manifests through the system of infinite nested structures that universe is, which looks to be a “soul” shaped as an individuality when “living” in a high order structure.
In this sense, all forms of matter, all structures, from particles to animals, and even stars or galaxies, are fit for “hosting” consciousness. We humans, are the first structure in the evolutionary chain who can go further and fully awake that consciousness (nirvana).
So, when you die, depending on your karmas and evolutionary stage, you might take birth as a human again or as a lower life form. Nature would give you a body/organism fit to your drives and desires, it’s up to you to decide. Read The Tibetan Book of the Dead for more information.
It’s a paradox, because in reality we don’t reincarnate neither die, we are brahman, god, atman, spirit, consciousness… but our subtle bodies do seek and find a next physical structure where to resume the karmic game going on, and the effect is that we “reincarnate” and continue to manifest in the phenomenological world.
Regards.