It is said that fortune favors the bold, but for the aquatic snail (Radix balthica), bold individuals may get some help from stronger shells. In a study published online today in Biology Letters, researchers investigated the “phenotypic compensation hypothesis”—the idea that animals that take more risks may offset the danger by developing stronger defenses. The team began by raising a population of 160 snails taken as eggs from a pond in Lund, Sweden. After 3 months, the snails were characterized as either bold or shy by measuring how long it took an individual to poke its head back out of the shell after being scared. A bold snail was defined as one that consistently stuck its head back out after 10 seconds or less, whereas a shy snail waited 15 seconds or more. Researchers then took several measurements of the animals’ shells and looked for correlations. On average, the bold snails had larger, rounder shells with wider holes—characteristics that make the shell stronger and more difficult for predators to crush. Additionally, when the snails were exposed to fish predators, bold snails survived better than shy ones despite their increased chances of being spotted. According to the authors, the risky behavior of bold snails may have increased the evolutionary pressure to develop better defenses, whereas for a shy snail, a stronger shell isn’t as important. The team also acknowledges that the causality might be flipped—that the improved shell may embolden the animals—citing the evidence that hermit crabs are known to take more risks when they are better camouflaged. Still, the team’s results support the phenotypic compensation hypothesis, and, at least for the aquatic snail, lend some credence to the old cliché.