Really? A spiders reaction to caffeine is your reason? I just quit caffeine. I'm ready for some conformation bias to justify my decision, but this is pretty weak.
I agree the spider-caffeine-thing is "weak". But it's a popular argument and I don't have anything more substantial at hand. Most people I know, that still drink coffee/caffeine do tell tales of feeling "wired" and "scattered" after consumption.
No jitters but if I take all 4 at once I get a pretty unpleasant "coming up" feeling for about 15 minutes. I usually just have 2 a day, and I'd recommend people start with 1 just in the morning.