In its natural habitat, must distinguish friend from foe. are abundant in the worm's environment and can be nutritious or pathogenic. Previously, we found that worms learn to avoid and through a small RNA (sRNA)-mediated pathway targeting the gene , and this behavior is inherited for four generations. Here, we show that learns to transgenerationally avoid another pathogenic bacteria 15 (PF15). The PF15 sRNA, Pfs1, targets the ephrin receptor through 16 nt of perfect match, suggesting the evolution of a distinct bacterial sRNA/ gene target pair. Knockdown of both induce PF15 avoidance, and loss reduces expression, placing both genes in the sRNA-targeted pathogenic avoidance pathway. Thus, multiple genes in this avoidance pathway can act as targets for bacterial sRNAs, expanding the possibilities for evolution of trans-kingdom regulation of behavior.