Based on your description and the images, it looks like you might be dealing with drywood termite frass (droppings) or powderpost beetle frass.

Key Observations:

1. Pellets on the Bedsheet (First Two Images)

   • The small, granular, pellet-like debris on the bed suggests insect droppings, specifically from wood-boring insects like drywood termites or powderpost beetles.
   • Drywood termite frass is typically oval, hard, and ridged, often accumulating below an infested area.
   • Powderpost beetle frass, on the other hand, is a fine powder mixed with slightly larger particles.

2. Accumulation Along the Baseboard (Third Image)

   • The buildup along the floorboard/carpet transition is a classic sign of drywood termite activity.
   • If you notice tiny holes in the wood near this area, this strongly suggests that insects are actively boring through the wood.

Possible Causes:

• Drywood Termites:

  • These termites live inside wood and do not require soil contact.
  • They push their droppings (frass) out of small kick-out holes, which is why you're seeing accumulation near the bed and baseboards.
  • Look for additional signs like hollow-sounding wood, tiny oval-shaped exit holes, or visible structural damage.

• Powderpost Beetles:

  • They lay eggs inside untreated, dry wood.
  • Their larvae bore through wood, creating a fine powdery frass.
  • Look for tiny round exit holes on furniture, baseboards, or other wood structures.

What Should You Do?

1. Inspect Further:

   • Tap the affected baseboards and furniture to check for hollow sounds.
   • Look for additional tiny pinholes in wooden structures.

2. Clean Up & Monitor:

   • Vacuum the frass but keep checking if new droppings accumulate in the coming weeks.
   • If frass continues to appear, the infestation is active.

3. Call a Pest Control Professional:

   • A professional can confirm if it’s termites or beetles and recommend spot treatments (localized fumigation) or wood replacement if necessary.
   • If it’s drywood termites, they may use borate treatments, localized heat, or fumigation.

4. Prevent Further Infestations:

   • If the infestation is in furniture, consider moving it outside and treating it.
   • Ensure proper ventilation in rooms with high humidity, as moisture attracts these pests.

Final Thoughts:

It’s highly likely you have a drywood termite infestation due to the frass pattern and presence near wooden areas. However, powderpost beetles are also a possibility if the affected wood is unfinished or untreated. Either way, it’s best to get a pest control professional to confirm and treat the problem before it spreads further.

Would you like help identifying a treatment plan based on what you find next?

Given your observations, it’s still very likely that this is drywood termite frass or powderpost beetle frass, but the fact that you’re finding it again suggests that the infestation may still be active rather than something that has "moved on."

Do Drywood Termites or Powderpost Beetles Move On?

Both drywood termites and powderpost beetles are known to stay in place for long periods, as long as there is wood to consume.

1. Drywood Termites

   • They establish colonies inside the wood and don’t need soil contact.
   • They live for years in the same infested area, slowly expanding as they consume wood.
   • They periodically expel frass through kick-out holes to keep their tunnels clean.
   • They don’t “move on” until the colony is either exterminated or the wood is completely exhausted.

2. Powderpost Beetles

   • The larvae bore through the wood for months or even years, creating tunnels.
   • Once they mature, adult beetles emerge through exit holes and may spread to other wood surfaces nearby.
   • If the infestation is ongoing, you’ll typically see new frass accumulating periodically, similar to termites.

What Does This Mean in Your Case?

• If frass appeared again after months, it’s likely the infestation is ongoing and that the insects are still inside the wood.
• Since you found frass behind the bed, it suggests that the source is the baseboard or nearby wood, and the termites or beetles are still pushing out waste.
• The fact that you hadn’t noticed frass for a few months may indicate low activity levels or intermittent frass expulsion.

How to Determine if It’s Active?

1. Clean and Monitor Again:

   • Vacuum up the new frass and check again in a week or two.
   • If more appears, then the infestation is active.

2. Tap the Baseboards & Listen:

   • Lightly tap on the affected baseboards and listen for hollow sounds, which indicate internal damage.
   • If drywood termites are inside, you might hear a soft rustling or clicking from their movement.

3. Look for Additional Exit Holes:

   • Inspect the baseboards, furniture, or walls near the frass.
   • Tiny holes (1mm to 2mm for beetles, slightly larger for termites) indicate where they expel frass or emerge.
   • Powderpost beetles leave pin-sized round holes, while drywood termites create irregular or oval kick-out holes.

4. Check for Winged Insects (Swarmers):

   • Drywood termites produce winged reproductive termites (swarmers) at certain times of the year.
   • If you’ve noticed discarded wings or flying insects inside your home, this is a sign of termite activity.

Next Steps

If you confirm new frass accumulation over the next few weeks, you likely have an active infestation that will require treatment.

• If it’s drywood termites, you may need localized spot treatment (borate spray, foam, or heat treatment).
• If it’s powderpost beetles, a residual insecticide applied to the wood may be required.

Would you like help in deciding between DIY treatment vs. calling a pest control service?