Pageview spikes

Every so often I look at the page view counts (traffic counts or hits) on this blog.  Naturally I get a good warm feeling as traffic increases over time.   Right now I get maybe 70 hits on an ordinary day.  Then there are extraordinary days where I get a spike of 250 hits, all in a short period of time.  I'm guessing that the spikes are not real readers, but computer programs sampling my blog perhaps to index my posts into search engines or perhaps some unknown reason.