It's not just me then. On a much smaller scale though, I've gone from about 30 to 300.
Your duck limerick contest could be super-popular (which is perfectly plausible, given its coolness), or it could be spamming. I've experienced this several times myself, where I'll receive a large wave of hits from no identifiable source. One of my posts received 53 hits in the span of a few seconds last night, so it happened to me recently.
WHile the duck limerick contest is doing well, I'm thinking SPAM! Things have finally quietened down!
Thank you for all your comments, which I love to read!