Sure they might as well, a lot of people use it anyways!
I was looking at a scientific study recently, were spiders were subjected to different stimuli, including LSD, cocaine, marijuana and other narcotics and CAFFEINE.
The study was aimed at observing the spiders general behaviors and spider web structure and production.
In the end it was found that narcotics didn't affect the spiders ability to carry out their general tasks and their spider webs were quite normal looking. BUT when subjected to CAFFEINE, the spiders were affected drastically and their webs were poorly constructed and were quite atrocious!
So hmmmm do you think caffeine affects us worse than marijuana?