So many times i had this chance, but believe me when i say the dood is quick! haha, anyway here is the picture.... I believe he is the tube that is going down into the mushroom... kinda blurry but like i said sorry, he's quick. I am not sure that this is what does the webs but I have reason to believe he is, otherwise it's concidence... hope this helps haha

PS if you know this isnt what is making the webs and you do know what the tublar thing is, please let me know because i have been wondering! thx a lot