A dactylic foot (known as a dactyl) has a long syllable followed by two short syllables (LSS or /UU)
Heptameter is seven feet per line.
We couldn’t find any examples of dactylic heptameter, which is hardly surprising as seven dactyls in every line would be unremittingly tedious.
However, just in case you were wondering what it might be like, we came up with these lines:
Why does a mockingbird never play badminton, is it because it can’t see
That a shuttlecock hit o’er a net with a racket is better than perching in trees?
The above uses dactyls throughout apart from the last foot of each line which is a long syllable on its own, and the start of the second line, which has two short syllables before the first dactyl. These provide much-needed variation.
A closer look at the feet in these lines
U = short syllable; / = long syllable; | = division between feet