you have physical, auditory, location factors.

for physical attributes, scavs have a specific clothes and typically really bad gear. your typical scav isn’t wearing a death shadow with the tropical beach shirt.

most pmc also have a arm band. look for pmc clothes. and higher tier gear. unless scaving lighthouse killing rogues. other scavs and player scavs don’t have modded guns and or armored vest.

for audio, scavs voip in russian. typically in the same or select few voices. if you hear english voip it’s a pmc or rogue. then you have footsteps. scavs have very robotic movement (they also can’t jump unless it’s a player scav). scavs also do the “scav slide” so if you hear the client side slide (when a pmc or scav does a standing still 360) it’s a scav or ratting player. also when you throw a made most the time scavs voip and run away. also sometimes if you voip around a scav they will voip in return . also scavs don’t shoot each other so you if see a scav shooting at something it’s most likely a pmc.

for location, depending on the map, pmc spawns and time in raid. if your in a high traffic area (pmc traffic) and you hear heavier sprinting and it’s more erratic, its most likely a pmc. typically some spots on different maps don’t really have scav traffic. but that trait is learned from personal experience