Why is great to be small. We discuss the ecology of land snails in fens and refer to our study with Brandon Schamp, a botanist from Canada, in which we investigated whether coexisting snail species in 145 treeless fen communities in the Western Carpathian Mountains differed more in size than would be expected by chance under limiting similarity theory. Contrary to expectation, coexisting snail species were significantly more similar with respect to body size. Specifically, smaller snail species were over-represented in fen communities in general, and this effect was accentuated in increasingly calcareous fens. Our findings support suggestion that traits related strongly to environmental conditions are more likely to be convergent, as small smail species have an advantage in tolerating freezing conditions over winter when refuges are limited.