A teat for a feeding bottle has a one-way valve 16 located remotely from thenipple of the teat to allow air to enter the feeding bottle to replace liquidsucked out of the bottle through the nipple while preventing liquid fromleaking from the bottle. The one-way valve 16 comprises an inwardly-orienteddepression having opposed mutually inclined sidewalls lea and 16b meetingalong a ridge having a slit. In the invention, when undeflected, the sidewalls lea and 16b make line contact with one another at the ridge and thethickness of the side walls is less than 0.4 mm so that, when acted upon by anincreased pressure in the feeding bottle, the side walls collapse against oneanother and make sealing contact along a surface that extends from the ridgein the direction away from it.
