I like my body more when I call it nonhuman
I don't have a human body.
Obviously. I'm not human, so of course I don't have a human body* - this isn't a human body, I didn't steal it, it's my body and it belongs to me. But my identification of my body as nonhuman goes deeper than mere semantic trickery. This body is the strange, complicated, often frustrating thing I use to interface with the world. It's a big part of my life! And I find it easier and more intuitive to do this whole "existence" thing when I don't try to force myself to view my body as human.
Imagine a human. What does their body look like? What can their body do? What do they spend their day doing?
Perhaps you imagined the typical human setup: a head, torso, two arms, two legs. Yeah, okay, I fit that pretty well. But, if you thought more deeply about the internal workings of the human body you imagined, things might start to diverge from what I am. I'm Disabled. I'm chronically ill. In imagining a human, you most likely implicitly imagined a person who can stand up without their body setting off alarm signals, and who can exercise without terrible neuroimmune symptoms that last for days. And that's not me.
Asked to imagine a typical human's daily activities, you would most likely picture them doing things such as going outside, working, walking home from the shops, maybe reading or watching TV in their downtime. These are all things that most humans' bodies allow them to do. But they couldn't be more alien to my housebound, Disabled existence.
Allowing myself to view my body as nonhuman helps me to free myself from impossible expectations. No longer constantly comparing myself to a biotypical norm allows me to accept and work with the body I have. This shift in thinking is liberating. I no longer have a failed human body, I have my own body: annoying, even traumatic at times, yes, but also unique, strange, beautiful. I want to get to know it as its own thing, not compare it with humans.
I often explain my nonhumanity as having two origins: dehumanisation due to disability and queerness, and something else, something innate. This is who I am because I choose to be, out of reaction to bigotry, and, at the same time, this is who I am because, well, this is just who I am. Both parts are important to my experience of nonhumanity.
The second part - the innate nonhumanity - is also relevent to my self conception of my body as a nonhuman body. Calling any part of myself human, including my body, feels wrong on an intrinsic level. Calling this body nonhuman allows me to claim ownership of it and feel more connected to it. When I let go and stop trying to force myself to view this body - my body - as human, my depersonalization/derealization (most likely, in this case, a manifestation of species dysphoria) lessens. Life feels brighter. Things feel more possible. I feel free.
In the end, it doesn't matter, really, why I call my body nonhuman. It makes me happier, and that should be reason enough.
Note: * many nonhumans view themselves as being human in this universe/life or as having a human body. This is a personal decision, and neither experience should be considered universal.