Mysterious Office "Worms": Newly Hatched Moth Larvae

Tiny, worm-like, webbing insects appearing then vanishing from mailboxes are almost certainly newly hatched moth larvae (caterpillars). Moths lay egg masses in hidden spots; hundreds hatch simultaneously, spin silk, then disperse rapidly—often overnight.

What Happened

• Eggs laid weeks earlier in/near mailboxes (cardboard, paper, cracks).
• Mass hatch → larvae spin silk, cluster briefly.
• Dispersal: crawl away to find food (paper, fabric, stored products) or get cleaned up.
• No adults seen because they emerged earlier or at night.

Action

1. Vacuum area thoroughly (cracks, corners).
2. Inspect stored paper/cardboard for more egg masses (fuzzy patches).
3. Discard infested materials.
4. Pheromone traps for pantry moths if food sources nearby.

One-time event unless breeding site persists. No health risk—just a nuisance.