How do Scav spawns work?

Question

I've played several games of Escape from Tarkov, some online, some offline, and noticed that Scavs don't seem to "already be there" when the PMCs first spawn.

My Obsersvations

When enabling "Scav War" in the offline options, Scavs shoot each other, so that alerts you to their presence. I noticed that it takes between 2 and 5 minutes for the first Scavs to begin shooting.

However, I also noticed that when I kill a Scav in offline mode and then stay in that position, one or more Scavs will quickly home in to this location.

My Questions

• At which point in a raid do Scavs begin to spawn? Is it pre-determined or random?
• How many Scavs spawn into a raid? Is there a fixed number and once they're dead, they're dead? Or are dead Scavs replaced after a certain amount of time has passed?
• Do Scavs spawn when a player (Player Scav or PMC) is close to that location?
• Is the spawn behavior of Sniper Scavs any different from regular Scavs?

Answer 1

Not all bot Scavs spawn at the start of the raid (some are always present), they'll slowly spawn in through the first ten minutes of the raid into a set of predetermined locations. This is done to prevent spawnkilling while your PMC loads into the game. Customs, for example, may not have the full set of scavs spawn near Scav Checkpoint as your character may also spawn there. Check back in five minutes they'll likely all be loaded.

More scavs do spawn in a raid, but they aren't bot scavs. They're player scavs! Players can spawn late into a raid at a different set of predetermined spawn points. It doesn't seem to be a fixed number of guaranteed spawns, rather it roughly correlates with the population of the Tarkov server you're playing on. Different maps will have different caps on the number of player scavs that can spawn. Likewise, these player-controlled scavs spawn at different times ranging from about five minutes from the start of the raid to as late as ten minutes before the end of the raid.

Scavs do not spawn based on the player's location, although some may spawn due to the player's actions or other external factors. On certain maps, such as Labs, heavily-armed Raiders will spawn when you call for any extract. On Reserve, a train automatically arrives which serves to drop off more raiders while also becoming an extract location itself.

Sniper scavs do behave differently than regular scavs. They cannot move down from their exposed position. These scavs can stand up or crouch, but will stay on their rooftop while they try to shoot you.

Answer 2

Scav timers depend on the map, and a fair bit of RNG. There is a minimum based on map size - you won't spawn with 5 minutes in Woods, for example, because it would be near impossible to get to extract in time.

The earliest I've gotten in as a Scav was 34 minutes on Lighthouse, and the latest was around 8 minutes on Factory.

In general, larger maps will spawn you in earlier and smaller maps will spawn you in later, but the exact numbers don't appear to have been published anywhere.