Caffeine increases life span in a manner that is non-additive with dietary restriction. Life span extension from caffeine and bacterial deprivation are non-additive at (A) 15°C and (B) 20°C; *P < 0.05 vs. ad libitum fed worms at the same caffeine concentration. (C) 5 mM caffeine does not reduce pharyngeal pumping at 15°C. Error bars represent standard error. *P < 0.05 vs. 0 mM on the same day.