Why are cockroaches still counted after the floor is clear?

Check the bucket, air vent, sofa, and later outdoor colony.

How do I clear the vent?

Open it and choose the suction or fan control to pull the insects out.

Repair the ultrasonic device, then defeat the giant final swarm with repeated powered flamethrower attacks.

Brain Puzzle: Tricky Quest level guide

hard

Poison visible roaches, freeze and suction hidden nests, lay traps, repair the ultrasonic device, then burn the final giant swarm.

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Spray the visible floor and sofa-edge cockroaches with poison.
Recover the control button and poison the bucket infestation.
Turn the temperature knob fully right to freeze the next kitchen group.
Open the vent and select suction to remove the cockroaches inside.
Place sticky traps on the active crawling routes.
Remove the ruined sofa and repair the ultrasonic device underneath.
Increase the flamethrower power and fire until the giant swarm counter reaches zero.

Board notes 5 details

Layout: Cockroaches fill a new apartment's floor, sofa, bucket, vent, kitchen, hidden furniture, and final outdoor colony under a red remaining counter.
Goal: Reduce the cockroach counter from near 100 to zero.
Opening: Spray the visible floor groups and recover the missing control button.
Danger Zone: The bucket, vent, sofa, and giant outdoor nest remain after the open floor looks clean.
Mechanics: Chemical, cold, suction, traps, ultrasonic control, and a fire boss phase clear successive infestations.

Why are cockroaches still counted after the floor is clear?
Check the bucket, air vent, sofa, and later outdoor colony.
How do I clear the vent?
Open it and choose the suction or fan control to pull the insects out.
How does the level end?
Repair the ultrasonic device, then defeat the giant final swarm with repeated powered flamethrower attacks.