FWIW You often find even smaller desiccant strips/bags in scrap hard disks, along with a tiny air filter.
Dessicant bags absorb water vapour from the air. As they clearly can't have infinite capacity to do so, how do you "dry" them out and store then after they have been exposed the normal moisture in the atmosphere for a while?
There is lots of duff info out there in interweb land regarding drying them out, like "5 mins in the microwave and you are good to go". The general ideas is heat them above 100C for a period, determined by their weight, long enough to dry them out. I suspect for tiny packs like these, heating them for an hour or so would do the trick. Not sure that microwaving them will work, but you could try that too.
If you want the scientific answer, weigh a new pack, soak it in water for an hour or so, weigh it again, the diffetence is the amount of water it can absorb.
Next, heat it to a suitable temperature to drive out the moisture (the silica gel will be fairly robust, not sure about the bag, so don't get crazily hot, maybe stick below 120C), weigh it every 15 mins till it returns to 90% or so of its original weight, and there is your answer.
Alternatively, given the low cost of these little guys, if you can't be bothered with all that trouble, and aren't worried by the "landfill factor" buy some more.
EDIT: Some reasonable instructions for drying out similar packs
here.Note, the instructions I linked to are on deg F not deg C, don't mix them up or you will probably set the packs on fire. 240F is around 115C if I am not mistaken. 240C on the other hand.. is 464F, and will make for very crispy bacon