because the wool contains lanolin
because they give off an oily/fatty substance called lanolin.
A fleece
The fleece of a sheep is like your own hair. It is oily like your hair. You shampoo your hair and that makes it softer and not as oily. This does help to prevent the fleece fibers from breaking off and being damaged. The fleece is really a winter coat for them.
its called a fleece
The word you're looking for is 'fleece'.
fleece
Wool is spun from the fleece of sheep.
The oil is known as lanolin
With electric shears - they used to shear them with hand shears
Sheep grow wool. When the wool is shorn from a sheep it is called a fleece.
After you cut a sheeps fleece you will want to wait at least six weeks for the new coat to grow in. You may choose to wait longer for a thicker coat, but do not cut the sheeps fleece any sooner than six weeks.
The oil on the sheeps' skin surface (lanolin) makes the wool oily.