Montane voles, in contrast, are not wired for monogamy. Sex feels good to them, of course, but the particular partner doesn’t matter. Montane voles don’t have enough receptors for oxytocin or vasopressin in their pleasure regions—so they never link the memory of a specific mate with the joy of sex. For a montane vole, any attractive member of the opposite sex will do. Only sexual novelty, not familiarity, brings pleasure in this species.
