Coffee can do strange things to animals. There's a study where NASA gave various drugs to spiders to see how it affected their webs[0]. Coffee had a stranger effect on the web than marijuana.
[0] https://web.archive.org/web/20210327150247/https://arachnidl...
Obligatory reference to this classic wildlife film from the Canadian Wildlife Service in Ottawa.
It's almost unbelievable.
More than anything this seems like a good reminder that spiders aren't human.
Salient point:
Caffeine is a chemical that plants evolved multiple times independently as an insecticide.