They have been hitting hard on 3 of mine. One got so bad I put a 1.25 minute crawl delay. It is like they got off the leash. I'm on a good server, but others are trying to see things too, and they are overdoing it.
My largest site has shown a small decrease in crawl rate over the last few days. Two of my smaller sites have shown a very definite large increase in crawl rate over that time. Not the highest but very near.
I have not the slightest clue what use that information is to me or what use I can make of it. Seems like a case of whatever will be, will be.