spring fever

It's spring fever. . . . And when you've got it, you want—oh, you don't quite know what it is you DO want, but it just fairly makes your heart ache, you want it so! It seems to you that mainly what you want is to get away; get away from the same old tedious things you're so used to seeing and so tired of, and set something new.

"Yes, missus," replied the negro, scratching his head, "de horses am berry lazy; spec dey's got de spring fever."