This may not be quite right, but at least it involves animals, if you consider insects animals, and it touches on some of the key elements of the squirrel feeds itself arduously.
Consider the fable The Ant and the Grasshopper. According to Wikipedia:
The Ant and the Grasshopper, alternatively titled The Grasshopper and the Ant (or Ants), is one of Aesop's Fables, numbered 373 in the Perry Index. The fable describes how a hungry grasshopper begs for food from an ant
when winter comes and is refused. The situation sums up moral lessons
about the virtues of hard work and planning for the future. (emphasis
The fable concerns a grasshopper (in the original, a cicada) that has
spent the summer singing while the ant (or ants in some versions)
worked to store up food for winter. When that season arrives, the
grasshopper finds itself dying of hunger and begs the ant for food.
However, the ant rebukes its idleness and tells it to dance the winter
away now. (emphasis added)
With regard to the OP's example and its desired (self-) motivational aspect:
"I worked all day and I feel like I didn't make any progress."
"Well, have you ever heard the fable The Ant and the Grasshopper?
You're the ant, and when winter comes, you will be glad of all your hard work. You will have prepared well."
One could frame the response of the last two sentences in numerous, and I'm sure, better ways.