Spider Silk Is Heavy-Duty Strength
Why don't spiders stick to their own webs? Initial theories included the idea that spider legs had an oily coating. This is not the case, seeing as spiders do not have oil-producing glands. However, only the tips of spiders' legs actually come into contact with their webs, and not all spider webs are sticky.
from Mental Floss
Key Facts In This Video
Only the tips of spiders' legs actually come into contact with their webs. (0:45)
Spiders pull their legs through their mouths as part of their cleaning routine. (1:07)
Not all spider webs are sticky. (1:46)