There was a time that I tried to read something heavy duty in the line from African American folk songs about snakes biting people on the heel. But now I figure these lines reflected the worry that people had who lived in areas where there are a lot of snakes-maybe this worry was even more pronounced in people who were barefooted, because they couldn't afford shoes, but I'm not sure about that.

Here's another song I found with a line about a snake biting a person on the heel. This song also has the line about falling into a hornet's nest:

OUTRUNNING THE DEVIL

I went upon de mountain,
An' I seed de Devil comin'.
I retched an' got my hat an' coat,
An' I beat de Devil runnin'.

As I run'd down across de fiel'.
A rattlesnake bit me on de heel.
I rears an' pitches an' does my bes'
An' I falls right back in a hornet's nes'.

For w'en I wus a sinnah man,
I run by leaps an' boun's.
I wus afeard de Devil 'ould ketch me
Wid his ole three legged houn's.

But now I'se come a Christun,
I kneels right down an' prays.
An' den de Devil runs from me-
I'se tried dem other ways.

Source: Thomas W. Talley "Negro Folk Rhymes" {Kennikat Press, Inc. Edition, 1968, p. 108; originally published by The Macmillan Co., 1922}