1.
Hay is grass which has been cut and dried so that it can be used to feed animals.
...bales of ~.
N-UNCOUNT
2.
If you say that someone is making ~ or is making ~ while the sun shines, you mean that they are taking advantage of a situation that is favourable to them while they have the chance to.
We knew that war was coming, and were determined to make ~ while we could.
PHRASE: V inflects