>>397938450
>ear a buzz and see a brief flash
That's the rift. It's never really explained in the game but they will do that and spawn an enemy. There's always one around critical areas and they can cover a large area for their spawn radius. Example the pervomay train station will have one rift and it'll cover the entire train station and a bit outside it. Meanwhile the blockpost in the same map will just cover that blockpost and a little bit of the street outside it. They can be a couple of different places but each area they cover will only have one at a time. They kind of howl and make a buzzing noise and will set off your detector so you can find them pretty easily. You've gotta make those your first priority though. Sometimes I'll ditch my rifle and ammo in a safe spot just outside a compound I'm about to clear and just dash in light with a pistol and injectors only to take out the rift and get out. Especially in kolhoz where armoured spetz mimics will appear and immediately full auto with their AS Val directly into your testicles. Also yeah melee weapons have a cooldown on them which is really long so if you don't kill in the first hit, you're dead. Machete does more damage than the knife and an overhead down onto the skull of a hollow fragment should kill instantly but you roll the dice there by being within melee range and potentially taking a hit. I always carry one mostly as a fork but I have used it in desperation a couple of times and lived because of it.