The phrase "tiny mouths" refers to very small openings or entrances to certain things, like the mouths of small animals or tiny openings of containers. Full definition
Thankfully, this set of four small rope toys is both perfectly sized for tiny mouths and also offers a variety of textures to explore and enjoy. (petsprinciple.com)
I, too, had the problem of having large nipples and a tiny baby with an equally tiny mouth. (babycenter.com)
The kibble itself is designed for tiny mouths, and helps promote plaque and tartar reduction. (happypetsnow.com)