"SOME biologists and neuroscientists will always be around who say what you want. If you can show that the mainstream opinion is against me, I'll happily concede the point, and thank you for enlightening me, but I doubt it."
Some studies of insect locomotion (which was where this discussion started) which use experimental data, modelling, or a mixture of the two to show that a great deal of locomotion sensing and control happens either in the limbs themselves before they reach any nerve centres, or in the thoracic ganglia. Nerve stimulation experiments have also shown that the characteristic "dual tripod" gait of hexapods is a mechanical oscillatory cycle that runs automatically when single nerves in the brain or mesothoracic ganglia are stimulated. The same is true for wing beats (which is some types share both muscles and central ganglia with the legs), which will cycle repeatedly when nerves in the thoracic ganglia are stimulated. The notable similarity in the data gathered from not only animals of the same species, but but those of different but closely related ones indicates that these movements are produced by a fixed "hardware" pattern generator, similar in principle to the electro-mechanical sequencers used in dishwashers and washing machines before microprocessor control became common:
(Note I apologise in advance for some of these only abstracts. Full scientific papers and book texts are hard to find on the web):
http://jn.physiology.org/cgi/content/full/82/1/512
http://www3.interscience.wiley.com/journal/45436/abstract
http://pt.wkhealth.com/pt/re/ejnr/abstract.00009274-200419070-00019.htm;jsessionid=KwpKVK0J1jTLRRXsZmb2QJJ53LlxD8s1Tnhv6l5Fqj9qNF2ncS7l!-1104825961!181195629!8091!-1
http://www.nature.com/nature/journal/v283/n5749/abs/283768a0.html
http://www3.interscience.wiley.com/journal/109692463/abstract
http://www.cell.com/biophysj/abstract/S0006-3495(65)86706-6
http://209.85.229.132/search?q=cache:5jTmyj1E8ywJ:biology.queensu.ca/~locust/Publications/locust%2520flight.pdf+insect+proprioceptors+ganglia&cd=75&hl=en&ct=clnk
"Oh really? You read it's mind then?"
There is absolutely no evidence that insects have anything that fits the description of a "mind" to read. Note though that some spiders may well have minds, e.g. Portia labiata, which displays a level of intelligence that makes many small mammals look like warm-blooded morons.
"Humans are predictable too. Doesn't mean they're not intelligent. They're just creatures of habit."
Humans are predictable en-masse, but not individually. Most insects on the other hand are entirely predictable individually, i.e. they always react in precisely the same way to the same sets of stimuli as another insect of the same species.
"Well, Jellyfish ARE pretty dumb, you know. The most complex behaviour I know of is in Box Jellyfish, which use simple visual contrast to avoid obstacles."
All jellyfish are sensitive to a variety of external factors such as light, orientation, water currents, temperature, and a variety of types of touch, so they're by no means as unsophisticated as you're trying to make out. It's notable that you avoid trying to deal with echinoderms, which like most animals with radial rather than bilateral symmetry, also lack central nervous systems.
"A kid's home robot project could probably outsmart it."
Which proves what, precisely? I had a clockwork beetle when I was a small child that walked with a dual-tripod gait and changed direction when it bumped into things, but that doesn't prove anything whatsoever about real insects.
"Nothing about that is disproportionate to what I'd expect from a simple nerve net, vs. what I'd expect from more intelligent creatures with complete, well developed brains."
You are transparently and obviously avoiding answering the question I asked, which I will repeat: where does the software that allows jellyfish, echinoderms, and other creatures without central nervous systems to interact with their environments in a variety of ways reside?
"This only backs up my argument that flies have more complex brains, and so more complex behaviours."
What this actually does is display a desperate and transparent attempt at building a straw man because you can't back up your original claims, which were: (1) walking around without falling over or bumping into things requires intelligence; (2) flies are running software; and (3) that fly preening behaviour is intelligent.