Theory:

There was a cricket (an insect similar to a grasshopper) which was young and not so wise. He had the habit of singing during happy times. During spring and summer seasons, the warm sunny weather allowed lush green vegetation, and all living beings got adequate food and water. In contrast, during the winter months - the whole place was covered with snow. There were no plants, leaves or flowers in sight. Therefore animals found it hard to find food at such times. The cricket which enjoyed during the active warm months failed to store for the future. He opened the cupboard and found it empty- there was not a small piece of food to be found, because he had not saved any food. Winter had started, and now only the cricket realized that he had not stored food. He wondered what will happen to him because he did not have any food.
 
The cricket had not saved any food for the future, and he wondered what will happen to him if he did not have food. He would have to starve without food if he did not do anything now. He was soaked wet and shaking because of the extreme cold weather. He gathered courage from the fear of being without food; he started his journey to visit the ant and ask his help. The cricket wanted to borrow from the ant and repay it in the future (tomorrow refers to the future, not the next day)
  • a staying place for the winter
  • a mouthful of grain(the quantity of grain that is sufficient for insects like cricket)
If the ant does not give him food and shelter, the cricket will die of lack of food and disappointment. The poet refers to the ant as "miserly" here. Miser refers to people to save a lot and spend very little. It can be given a positive meaning here, to praise the ant's quality of thinking about the future and preserving food for the cold days.
 
The cricket went to the ant and asked for help. The ant said he was the cricket's servant and friend. But the ant also said that ants don't borrow or lend anything. The ant further asked the cricket what he had been doing when the weather was warm enough for him to work hard and save food. The cricket replied that he was very happy when nature looked good and bright. He added that he sang all day and night, out of happiness. The ant replied sarcastically that if he had been singing during the summer, now he can go and dance till the winter ends.
 
Here the poet refers to the mockery made by the ant. The ant mocked the cricket because the ant was worked hard during the summer months to relax and have food during winter; whereas the cricket, had sung songs all day during summer and now came to the ant for help. This also refers to the poet mocking lazy people. We should always think of our future and save according to our needs. When we have money we should not spend everything, we should save for the hard days.
 
If we have a valid reason for not saving for the future, others may show pity on us and help us out of a difficult situation; but if we enjoy happily instead of working hard, nobody will come forward to help us. The summer and winter may also refer to our young and old age - if we work hard during our young years and save wisely, we can live happily during the old age without asking help from anyone.
 
The ant refused to help the cricket. He quickly closed the small opening in the door and shut the cricket out of his house. The poor cricket had no other choice, but to leave the place.
 
The poet says people think of this story as a fable (an imaginary story), but he feels it could have even really happened. The moral of the story is very true that it can happen actually in real life too. He refers to the cricket in the poem as a four-legged cricket, and humans as two-legged crickets. If we are silly enough like the cricket, we will also end up starved and disappointed. We should always think ahead and save for the future.
 
Meanings of difficult words:
 

Words

Meanings

accustomed

habitual,  usual

crumb

a small  piece of bread, biscuit etc.

gay

bright,  vibrant

dance  the winter away

spend  time dancing, during the winter

dripping

so wet  as to shed drops of liquid

famine

scarcity  of food

folks

people,  in general (casual)

hastily

urgently,  quickly

miserly

a person  who hoards wealth and spends as little money as possible

quoth

said (in  Old English)

starvation

suffering  or death due to lack of food

wicket

an  opening in a door, gate or wall