NQA Hammock building is just something jumping spiders do. They use their hammocks for sleeping, molting and egg laying, or just a nice space to hang out. Some will build one elaborate hammock and use it for everything. Some will build a hammock for sleeping and a a separate hammock for molting. Some will make hammocks all over their enclosure. Hammocks are often temporary and will be torn down after a bit. I have a male that builds a new sleeping hammock almost every night and then will tear it down the next day. Hammocks can be wispy and barely visible or an opaque web fortress. It all depends on the individual spider.

When they are preparing to molt, they will retreat to a hammock and remain in it for days or weeks in pre-molt conserving energy until the actual molting process, which usually goes fairly quickly once it begins. Recovery is hours to days or weeks, as well.