I do plenty of d key running with my sorc. I have done at least 250 runs. Only recently did I obtain a Storch that increased my skills by a good amount. I went from 12k lighting damage to 16k lighting damage.
And after many many games, I notice that it seems like EVERY time there are snakes, and usually there are a high amount than normal too. It appears that by being better geared, the game becomes aware of it. The first 200 games I did without an Storch, snakes spawned about 1 game out of every 4, and then not that many. With the storch, I spawn snakes at least every 3 games out of 4, and they spawn in massive amounts. I recently ran into a clump of SEVEN snakes all circling around nihlatak. This never happened before.
Can anyone confirm or deny this relationship with 100% certainty?
As far as I'm aware of, there should be no correlation between monster spawn types and rates and your equipment. I think the monster types picked are based on the in game time of day (ie. night vs day) so a possible explanation is that if you're running the areas faster, you're running into more snakes since they're more likely to show up at an earlier time of day. But this assumes that the game starts at the same times of day each run, and from what I see, it appears random.
So most likely, it's probably a coincidence. If you want to find out, start taking hard stats, and do runs with and without your torch to try to determine the correlation.
Preliminary evidence gives support to Oblique. I have started collected hard stats, and will report them sometime in the future, but for those interested. Snakes appear to NOT spawn during in game daytime hours. I have yet to run into a game that does not agree to this formula.