Terms like biolumiscent isn't just reserved for fireflies or glowing eyes of a predator, the human body literally glows in the dark, acccording to a study conducted by scientists Daisuke Kikuchi and Hitoshi Okamur in 2009. Our body emits ultraweak photons through the changes in our metabolism resulting in photo emission. This light however, is extremely faint, about 1000 times fainter the threshold of our naked eyes. Using hypersensitive cameras, the researches monitored this emission which differed from the standard infrared emission due to body heat.
Enzymatic reactions inside a firefly makes its body glow (Source)
HERE'S A VIDEO WHY FIREFLIES GLOW
Weak, but visible bio-lumiscence is a product of enzymatic reactions going on inside organisms such as fireflies and angler fish, however the research also suggests that every other organism is bio-lumiscent to some extent, and emit extremely weak light from their bodies.
This means you, me and the animals around us, are all "glowing" no matter how faint it is. It's not just a compliment.