A "dyke" is a small levee or dam.
>>
How does a small levee or dam ride a motorcycle?
Dictionary.com says that dike and dyke both mean:
1. a. An embankment of earth and rock built to prevent floods.
b. Chiefly British. A low wall, often of sod, dividing or enclosing lands.
2. A barrier blocking a passage, especially for protection.
3. A raised causeway.
4. A ditch; a channel.
5. Geology. A long mass of igneous rock that cuts across the structure of adjacent rock.
In any case it was a Dutch boy in the story who put his finger in the dike, not a Danish boy.
From that first line, I thought you were writing a poem.