Not you chewing. The rats.
Why chewing, you might ask? The authors of this study are using chewing as a way to induce “active behavioral coping”. And while the idea has merit, the data make me not so sure.
(Hey wait! That’s not a stick! Source)
Helmreich et al. “Active behavioral coping alters the behavioral but not the endocrine response to stress” Psychoneuroendocrinology, 2012.