Does pepper repel ants

Yes, ginger repels ants.

Specifically, the plant in question (Zingiber officinale) contains essential oils which have their role as natural repellents and in traditional medicine. Terpineol is one such oil. Depending upon which isomer is involved, terpineol may be used in perfumes or in repellents. It will be even more effective than the active ingredient carbaryl in suppressing ants when they behave as garden and household insect pests.