Thanks for the help all. I thought of 3M strips but it says not for use on vinyl. I was thinking when it got cold they wouldn't hold. I'm attaching the spiders on the side of the house. I did find vinyl hooks, so i'm going to order some and see how they turn out!
When I hang things from our siding I take advantage of the trim to tuck anchors behind or under to support my props. I wouldn't try to support too much weight this way , but I've done it with bats, spiders, freaky fabric hanging moss, rats, and christmas lights. You can tie fishing line to small finishing nails, then wedge the nails under the upper trim to support spiders and make anchor points for webbing. rat tails can be slightly tucked under window trim to pin them to the ledge. Just be careful not to force anything and damage your trim or siding.