In 1948, German pharmocologist P. N. Witt started his research on the effect of drugs on spiders.
Witt tested spiders with a range of psychoactive drugs, including amphetamine, mescaline, strychnine, LSD and caffeine, and found that the drugs affect the size and shape of the web rather than the time when it is built. At small doses of caffeine (10 µg/spider), the webs were smaller; the radii were uneven, but the regularity of the circles was unaffected. At higher doses (100 µg/spider), the shape changed more, and the web design became irregular.
All the drugs tested reduced web regularity except for small doses (0.1-0.3 µg) of LSD, which resulted in more ordered webs.