Put real spiderwebs on paper. preserve a spiderweb on paper to explore/look at. or put the black paper behind it so it can be seen in detail and then take a picture so you don't have to destroy the spider's web.
Take a look at how we plan for outdoor learning. Organizing learning opportunities in kindergarten can be easy. We try to encorporate as many learning opportunities as we can in math, language, science and the arts!