I just read about people putting lights under their skin. I must say, that sounds odd.
Then I considered. I think people are just jealous of the skills, tools, and adornments that animals have.
Tattoos? Tigers, chameleons, in fact, most animals are rather more decorated than we are.
I have heard some geeks put magnets in, to be able to 'sense' magnetic fields. Birds do this, I gather, to migrate.
Mechanical sniffers? Dogs got ya covered.
Mouse traps? Cats would sneer in contempt. (Again.)
Swim fins, the fish would count as baby steps, so to speak.
We have the ability to mimic a lot of different creatures, for our own use.
So, lights? Hmm... I think fireflies and angler fish would consider us posers...