It's been a while for me on hivetool but this week I bumped into this:
http://matpalm.com/blog/counting_bees/
i have not investigated it further but found it usefull to share.
a place for hive monitor developers to discuss Hardware and Software
Tom Goddard developed a video-based bee counter several years ago. He just spent a couple days on it and never got back to it, so as he says, it's a bit kludgey. But still rather cool. I suspect the JeVois cameras ($50) with 120 fps would work well for this application -- even though they're pretty low rez. Here's a link to Tom's work. http://sonic.net/~goddard/home/track_feb2015/track_feb2015.html
And the JeVois cameras (not what Tom used) -- http://jevois.org/
I like to look into the jevois camera, i think it could do more than just count like size bees or find and count drowns,
or even find a queen coming or going.
it could find intruders too.
to do all the computing in the raspberry pi would be to much.
and it could most or all the work and send a small bit of data out to log on the network.
the bad think is it's not weather proof and it can take .800 amps more ,bigger power supply and more heat.
I ordered one to see if it go into the enclosure i'm putting on my hive ( see Enclosure forum )