Snugly in a rug the little bug
slept
And then in with the vacumn
the cleaning maid
crept
Up into the vacumn the little bug
went
Snug as a bug in a vacumn
no assonance to that
no sense either

So the bug crawled out
and found another rug to sleep in
In a house with no maid and no vacumn

snug as a bug in a maidless house rug