Wild Diet
Wrens are primarily insectivorous, and don't often appear at bird feeders. In the wild, wrens eat spiders, beetles, caterpillars, flies and other insects. They also will consume snail shells to provide calcium and digestive grit. Wrens will eat nuts, seeds and berries when insects are unavailable.
Feeders
These birds are rare visitors to feeders, and are most likely to consume seed in the winter, when other food supplies are scarce. Black oil sunflower seed, peanut hearts and nutmeats are the best seed to attract winter wrens.
Suet
Wrens also may consume suet cakes, with or without seed, in the colder months. Place the cake in a suet feeder to prevent squirrels and larger birds from stealing it.