HOW TO HANG THEM
Start at the ceiling and work down.
The arrangement that works is a swarm, not a grid. Begin with the smallest bats tight together near the ceiling or the top corner of a window, then let them thin out and grow larger as they come down the wall. Clean the dust off first — adhesive strips are reusable but they need a dry surface to grip. Avoid vents, where the airflow will work them loose.
Twenty minutes and a stepladder.