Moths named for their regular appearance near the dead. Their wing patterns act as camouflage.

Several bone moths flutter at the edges of your lantern’s beam. Their white bodies are accented with skull-shaped black markings on their wings. - Outbreak in Undercity (RPA-ADV3) 

Bone moths are attracted to the smell of blood;

You pull the inkwell of blood from your pack and find that the smell of fresh blood attracts a number of bone moths, who swarm around the jar for a moment but then fly away again.

You drip a few drops from the inkwell onto the lantern’s flame. The smell of burnt blood draws a small swarm of bone moths, who flitter about in the smoke. They seem intoxicated by the aroma, and their wings shine with an eerie luminescence. - Outbreak in Undercity (RPA-ADV3) 

Bone moths flock to your inkwell of blood when visiting the Ossuary of the Old Order.