When should I change the sticky pad in my Safer SH502 Indoor Fly Trap?

[DiHarper]

For optimal performance, the Safer SH502 Indoor Plug-In Fly Trap's StickyTech Glue Card should be replaced approximately every 21 days. However, the exact timing can fluctuate. You should replace the sticky pad sooner if it becomes completely covered with insects or if it seems to have lost its stickiness. Regular replacement of the sticky pad is essential to maintain the fly trap's efficiency in catching and eliminating indoor pests.