Though they share some similarities, one of the most important facts to keep in mind is these two birds belong to different families. Woodpeckers are much larger in size than Eurasian nuthatches. There are some types of woodpeckers that can measure as long as 20 inches and weigh 20 ounces.
Some people think they’re related because both birds spend a lot of time tapping on the trunks of trees. A woodpecker uses this sound as communication with other woodpeckers. Alternatively, Eurasian nuthatches tap on the trunks of trees as they are foraging for bugs.
The habitat of these birds is another reason why some people think they are related. Many Eurasian nuthatches make their nests in tree cavities abandoned by woodpeckers. So, a bird flying in and out of a hole in a tree may not necessarily be a woodpecker!