New keepers often write to ask how to stop their arboreal from covering the enclosure in silk. The short answer: do not. Webbing is what an arboreal tarantula does with a space it has accepted.
What the web is for
The silk tunnel is a home, a trip-wire system and a moisture buffer all at once. Vibrations travelling along the silk tell the spider that prey has landed before it ever sees it. Inside the tunnel, the air is slightly more humid and much more still than outside, which is why a spider in a well-ventilated enclosure can still sit in a comfortable microclimate whenever it wants to.
Reading the placement
- High in a corner: normal and healthy. That is where an arboreal wants to be.
- Down at the substrate: often a sign the upper enclosure is too dry or too draughty, or that there is nothing to anchor silk to higher up.
- Sealed shut, all entrances closed: usually pre-moult. Leave it entirely alone and remove any live prey.
- Suddenly abandoned: check for mould, mites or prey remains inside the tunnel.
When to clean
Remove uneaten prey and boluses if you can reach them without tearing the structure. Otherwise leave it. A full teardown resets weeks of work for the spider and is the most common reason a settled animal starts pacing.
If the whole enclosure eventually becomes an opaque wall of silk and you genuinely cannot see the animal, rehouse rather than renovate. Move the cork with the web on it into the new enclosure so the spider keeps its own scent and structure.
Webbing over the vents
Arboreals will silk across openings. A thin layer over a 3 mm hole field barely changes the airflow, because the total open area is so large. If a spider consistently seals one band completely, it is usually telling you there is a draught it does not like: move the enclosure away from the door or the radiator rather than tearing the web.