Silica gel becomes ineffective once they’re saturated with moisture (ie, they can only absorb so much). Out in the open, it takes about a day to become saturated.
Always close your container/ziploc bag when the packet is inside.
Good news is, you can refresh the silica gel by microwaving it!
Microwave for 10-20secs, depending on the ovens power and the size of the packet. Make sure you pay attention to it and stop microwaving if you see smoke (not steam) coming from the packet.
The packet will be hot once zapped (if it’s not hot, zap it again), so be careful when taking it out of the microwave, use tongs/tweezers to pick them up.
*** Do not put the hot packet back with your glue! Put it in an airtight jar and fridge it for about 5 mins to cool it down first. Once cooled, you can put it back with your glue ***