Caffeine is a stimulant that most people ingest at some point, in the form of coffee, tea, fizzy drinks or chocolate. To test some of its psychological effects, and also those of other common drugs, scientists administered them to spiders to see how they impacted on web construction.
The most famous of these experiments was conducted by NASA in the Nineties. While marijuana led to slowly spun, incomplete webs and benzedrine (‘speed’) led to fast-spun, poorly organised webs, it was caffeine that had the biggest effect. It almost completely stopped spiders spinning webs at all, except for a few poorly organised strands with no structure.
Caffeine is also a natural pesticide, with some plants having developed caffeine within their seedlings to protect against insects. While caffeine kills certain bugs that feed on these plants, others have adapted to it and are unaffected, such as many beetles.
Answered by Aneel Bhangu