5000 hits, 100K in download bandwidth

Quick question? Apparent surge in traffic that I can't trace back to specific referals or normal behaviour of visitors. Normally when traffic goes wild so do downloads of book related content and referals from a specific source. Book reviews or commentary posted at specific sites normally drive traffic surges.

I suspect one of the spiders has gone wild and is slurping abnormally. Any one out there who is noticing the same trend on their web logs