I've found when teaching rhyming poems, there are kids who get it easily and kids who really struggle. Then with limericks, you through in a different meter along with the rhyming patterns. It's always been one of the more difficult types of poems for kids to understand well enough to write their own.
If you've been teaching limericks this month, or any other time, you might be interested in this episode of The Electric Company on PBS. You can show it to your students for another layer of exposure. It addresses both the rhyming pattern and the meter in a poetry slam episode. Cute, yet still appropriate for upper elementary.
I've included the link to PBS as it was the only way I could find to connect the video to this blog. It won't go straight to the video. Select the Electric Company from the right side bar (currently looks like a girl with a purple shirt) then select to brows episodes. The Limerick Slam will be there.
The Electric Company Limerick Slam