fairy soup - happy hooligans - outdoor sensory activities for kids. This is also a free activity you could consider mentioning to parents; a trip to the local park and then play at home. Also called a messy mixture, or "perfume making"
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.