Spotting an adult brown recluse in your living space is unsettling enough, but finding an egg sac elevates every homeowner's anxiety to a whole new level. Capable of harboring dozens — sometimes over 50 — spiderlings each, a single sac hidden behind your drywall or stored boxes means time is of the essence. Unlike the neat, symmetrical webs of everyday house spiders, a brown recluse egg sac sits in a messy, off-white wad of loose silk. If you've found an egg sac, it usually means a whole family has set up camp nearby. While you can handle the immediate threat of the sac, relying solely on DIY brown recluse pest control hacks is notoriously ineffective because they hide in such hard-to-reach areas.