I installed a search tool on this site, mainly for my own use in hunting down previous posts. I picked one that has a very large limit, which it will be a long time before I reach, and also one that I can index manually.
I discovered something. I found this out simply due to a hunch, based on no conscious technical knowledge on my part.
A while back I went into my Blogger settings and changed "Add your blog to our listings?" to NO. I did this so that my blog wouldn't be included in the "next blog" button function anymore. This way my web stats would be a lot more accurate, and the web counter that I recently installed would be more accurate, because it would eliminate random hits from that "next blog" thing.
Whatever this "NO" setting does, it also prevents the site from being spidered by certain search engines. I'm not sure exactly which ones or how extensive, except that, for sure, Picosearch and Freefind are both rendered inoperable by this setting.