A: The name Nuthatch probably results from the corruption of the word "nuthack" which refers to the Nuthatch's habit of hacking away at a seed with its beak until the seed opens. The white-breasted Nuthatch is a common visitor of bird feeders. It typically takes a single sunflower seed and flies to a nearby tree, wedges the seed into the bark and hacks it open with repeated blows from its bill. In a study of the white-breasted Nuthatch's seed catching behavior, it was found that they selected unshelled sunflower seeds approximately 25% more often than seeds still in the shell. It appears that this preference is driven by the fact that it takes the Nuthatch about half the time to transport and cache an unshelled seed than it does a shelled one. White-breasted Nuthatches will often store seeds for retrieval later in the same day or as a quick source of food for the next morning.We also see Pygmy Nuthatches who favor living among pine trees and red-breasted Nuthatches specialize in spruce and fir trees. The white-breasted Nuthatch is a common bird of deciduous forests and wooded urban areas. Known as the "upside down" bird, it is often observed creeping headfirst down tree trunks while searching cracks and crevices for insect food. The brown-headed Nuthatch is one of the few birds known to use a "tool" to find food. It will take a loose flake of pine bark in its bill and use it to pry up other scales of bark in search of prey. A nuthatch's foot has one big toe (the hallux) that faces backward, while its other three toes face forward. It is able to walk head first down the trunks of trees by moving only one foot at a time while the hallux toe on the other foot holds firmly to the bark.Nuthatches are monogamous and defend a territory throughout the year. The female white-breasted Nuthatch rarely strays far from her mate and stays in constant vocal contact when they are more than a few yards apart. The female mate plays the dominant role as "watchdog" when they are together, leaving the male more time to concentrate on hunting for food. During the winter, white-breasted Nuthatches will often forage together with other birds such as titmice, chickadees, and Downy Woodpeckers in a group known as a foraging guild. Nuthatches are able to recognize the alarm calls of these species and can thus reduce their own level of alertness by relying on vigilance of these other species.The white-breasted Nuthatch is known to bill-sweep a crushed insect around their nest cavity's entrance hole. Presumably to deter predators with the chemical-defense mechanisms from the insect. The Red-breasted Nuthatch will line the entrance to its nesting cavity with drops of sticky conifer resin. It is thought that this may be a tactic to discourage predators or nest competitors from entering the cavity. The nuthatches avoid the resin themselves by diving directly into the nesting cavity without ever touching the sides of the entry hole.The Pygmy Nuthatch is the only songbird that uses two different survival techniques simultaneously in order to endure cold winter nights. It roosts inside a protected tree cavity where it huddles together in a communal group with other Nuthatches and it conserves energy by lowering its metabolism and body temperature. Pygmy Nuthatches have never been observed to roost alone. They will always roost at night in a communal group which may contain up to 100 birds. This tightly packed mass of birds can warm the roosting cavity by 40 degrees F or more over the outside temperature. Pygmy Nuthatches can stay in their roost cavity for as long as 40 hours without feeding, enabling them to survive short periods of very severe winter weather. A Pygmy Nuthatch's diet switches from eating mostly insects and spiders in the summer to primarily eating seeds in the winter. It visits feeders where its favorite foods are sunflower seeds and suet. Local bird expert Larry Collins owns Wild Birds Unlimited, 2454 Hwy. 6&50, which caters to folks who want the best backyard birdfeeding experience possible. Email your birdfeeding and birding questions to email@example.com and he'll answer them in his bi-weekly Q&A column in the Free Press.