Compassion
Compassion is an emotion experienced by the ant in regards to the plight of the grasshopper. It is an essential component of the curious symbiosis joining these two species. It enables the grasshopper to live in comfort without taxing abilities or virtues it does not possess, and the ant to live a life of toil that is blessedly short.
One of the more subtle examples of the balance of nature, it, alas, suffers from certain defects which nature seems powerless to correct. Due to the asymmetry of the relationship, the grasshopper never develops skill or virtue, and any vestigial skill or virtue it may have possessed upon entering the symbiosis is quickly atrophied.
Meanwhile, the inability of the ant to fully compensate for the inefficiency of the relationship by expanding production inevitably results in the ant dying penniless, thus leaving the grasshopper with no visible means of support.
Now, if the ant truly cared for the grasshopper (rather than giving mere mandible service - ants don't have lips, you see), he would have left his remaining possessions (to wit: his ability and virtue) to the grasshopper in his will, rather than taking them to his grave.