Sumichrast's Wren is insectivorous. Snails are an important element in the diet, with at least four species known to be consumed by the wrens (Pérez Villafaña et al. 2003). Other documented food items include a variety of invertebrates, including an annelid worm, a spider, millipedes, Hemiptera, various beetles (Chrysomelidae, Curculionidae, Heteroceridae, Hydrophilidae, Scarabaeidae, and Tenebrionidae), Lepidoptera (adults and larvae), Orthoptera, Diptera, Formicidae, as well as the occasional small fruit (Pérez Villafaña et al. 2003).