The short version
A Snare Flea hangs from the ceiling and drops on your head. Once it is on, you cannot get it off yourself.
Look up before you walk through a room. That habit solves almost every Snare Flea problem.
What a Snare Flea is
Snare Fleas are indoor entities that wait on ceilings. They do not chase you across the facility.
They sit above doorways, corridors and rooms, and they wait for something to walk underneath.
The danger is not the creature. It is that everything interesting in this game is on the floor, so almost nobody looks up.
How the attack works
The attack is short and it happens fast.
You walk underneath it. That is the trigger. Nothing else sets it off.
It drops. It lands on your head and clamps on.
It suffocates you. While it is attached you take damage and you cannot remove it. You cannot fight, and you cannot run properly.
It does not let go on its own. There is no waiting it out. Either someone hits it, or the run ends for that diver.
The whole encounter is decided in the second before it drops. After that it is a rescue problem, not a combat problem.
Spotting them before they drop
They are visible if you look. That is the useful part.
Scan the ceiling when you enter a room. A quick look up at the doorway costs one second.
Watch for movement. They shift and twitch on the ceiling. Stillness and motion both show up once you know the shape.
Listen. There is an audible cue associated with them being active overhead.
Treat dark ceilings as unknown. If you cannot see the ceiling, do not assume it is empty. Bring a light and check.
The habit that works is checking at the threshold. Look up at every door before you walk through it.
How to move underneath them
Sometimes you have to pass under one. There is a safer way to do it.
Move at walking pace, not sprinting. You need to be watching the ceiling, not the floor.
Keep your light angled up as you cross the space under it.
Cross one at a time so the rest of the crew can watch and react.
Have a partner ready. If someone is watching with a shovel, a drop is survivable instead of fatal.
The rule of thumb is that you never cross under a ceiling you have not looked at.
What to do if one is on a teammate
This is the part crews get wrong under pressure, and the correct response is simple.
Hit the flea, not the player. A shovel swing at the diver’s head removes it. Friendly damage is the lesser evil here.
Do it immediately. The suffocation timer is short.
One or two swings is enough. It is not durable.
Then move. The room may hold more than one, and the noise of the rescue may have drawn attention.
A crew that practises this once will handle it calmly every time afterwards.
Why solo divers should avoid them entirely
For a solo diver, a Snare Flea is not dangerous. It is fatal.
There is nobody to hit it. There is nobody to call. Once it drops, the run is over.
That means a solo diver has to treat every ceiling as a hard check. Look up at every doorway, and route around rooms that hold more than one.
Solo divers should also avoid narrow corridors with low ceilings, where there is no room to step aside.
Where they sit
Knowing the likely spots makes the ceiling check faster.
Doorways and thresholds. The classic ambush point, because you are looking through rather than up.
Corridors with low ceilings. Easy for them to cover the whole width.
Rooms with a lot of scrap. You will be looking at the floor there, which is exactly the wrong place.
Near the entrance on some layouts. Check the ceiling on the way in, not only on the way out.
If a room has several, go around it. There is no reward for walking under a cluster.
Mistakes that get people killed
- Never looking up. Everything else follows from this.
- Sprinting through rooms. You cannot watch the ceiling at a run.
- Splitting up so nobody can rescue. A flea is only survivable with someone beside you.
- Hesitating on the rescue. Swing at the flea straight away.
- Walking under a cluster to save time. Go around.
Reading it in the bestiary
The Snare Flea is one of the 16 indoor entities in the monster database. That table lists every entity with its location and hazard rating where the source data provides one.
Our source data does not populate hazard or health for many entities. We describe behaviour rather than invent numbers, because the behaviour is the entire counter here.
Related guides
- Indoor monsters guide — all 16 facility entities and how they differ.
- Solo guide — why some entities are far worse without a crew.
- Co-op guide — the rescue habits that keep crews alive.
- Survival guide — exits and getting out before it matters.