Mildgyth
Senior Moderator
Humata, Hukhta, Hvarshta
@Wiimeiser
That’s not how biology works.
My headcanon is that they do go into heat, but that only means that these are the only times in the year they are ovulating, and thus can get pregnant; while it makes them more slightly susceptible to arousal, it’s relatively easy to get through it without necessarily having intercouse with anypony else. Most manage it; otherwise they’d quickly be stuck with about 10 foals or more.However, estrus time also differs wildly for every mare, and happens about six times in a year, or else all ponies would be born in the same small period of time.