Re: How does woodpecker know where to find the worms hidden in the trees?

Hi Jennifer,

I thought that it might be hard for me to answer this question, because I live in New Zealand (on the other side of the world from you) and we have no woodpeckers here at all. However, I found the answer for you on the web.

Quite simply, the woodpecker can hear the insects. Once it has detected the sounds of insects gnawing or moving within the bark or wood, it begins to hammer persistently in pursuit of its prey. Trees are not injured by these birds; the disfigured bark soon heals. In fact, woodpeckers save many trees from injury by insects.

Woodpeckers can sometimes be confused by the hum of interior electrical wires and appliances. It can start pecking holes in your house because it thinks that the humming noise means that there is a colony of tasty insects hiding behind the planking.

Once the woodpecker has made a hole, they can use a very special piece of equipment to help them. That is a long, elastic tongue. The tongue has barbs or glue on the end, and it can get around curves and get the ants that are scurrying around in their tunnels.

[Moderator addition: Unlike the muscular tongues of humans, the tongues of birds are supported by a rigid cartilage-and-bone skeleton called the hyoid apparatus. The hyoid horns of some species of woodpeckers can grow all the way up to the top of the head and, in some species, grow around the eye socket, or even extend into the nasal cavity. The horns of a bird's hyoid serve as an attachment site for muscles which originate in the lower jaw and pull the horns forward and against the skull when they contract, thrusting the tongue out of the mouth like a spear. Please see Talk.Origins for more. -- Steve Mack]

Sometimes a woodpecker is pecking away at a house or tree for a different reason. Woodpeckers do not sing to proclaim their territories like most other birds of the backyard. Instead, they tap rapidly on a hollow surface that makes a loud noise. This is called "drumming" and it is used to proclaim their territory to other woodpeckers. It is very different from pecking for food or nest holes because it does not often make a hole in the drumming surface--it just makes a loud noise.

The behavior usually starts in late winter and continues into spring. Sometimes antennas or other metal surfaces on houses make excellent drumming spots for the woodpeckers because they are loud and hollow-sounding. The best way to combat the behavior is to put something over the drumming spot that dulls the sound, like a piece of soft, foam rubber. If the spot no longer makes a loud noise when the woodpecker taps on it, it will abandon that spot and look for another, better location.

Some nice easy to understand information on woodpeckers can be found on this page and here is where I found the item on "drumming".