ooh, look an Islander 😊

Combination of these two should show you that mice react similarly to human reactions to oral ingestion of capsicin:

Innate liking and disgust reactions elicited by intraoral capsaicin in male mice
Acute oral toxicity of capsaicin in mice

here is test that uses pain caused by capsicin to test local anesthesia:

orofacial capsaicin test in rats

Does this prove that capsicium causes pain?

Edit some more research regarding the rodents:
Tree shrews can tolerate hot peppers:
Changes in TRPV1-Mediated Physiological Function in Rats Systemically Treated With Capsaicin on the Neonate

By this researcher they do feel the “pain” from it:

capsaicin as a rodent aversion agent