This is a game, which means that there are rules.
In-game, a couple of days ago a friend of mine pointed me to an 0.6 system which was heavily ratted. So far I've done three haunts there (and I think the rats have "learned" to stay away), but it throws up the question:
What sort of system maximises the rat revenue ? (without getting yourself killed ?)
Presumably you want a low security level, and a lot of belts (rats tending to congregate at the belts (well, the shootable ones)). But do the surrounding systems affect the calculation ? I'm using the word "calculation", because, in metagame terms, the rats only exist because the EVE game-system programme puts them there, and this is, logically, done through a mathemetical formula which says how many rats, of what size, and how often (plus or minus a random time).
Does the amount of ratting (or rat-farming) affect how many rats come along ? It isn't as though "chaining" happens (so far as I know) in hi-sec, but do the formulae take account of how quickly rats are killed ?
Does the allocation of missions to a system affect how many rats are programmed to materialise ? If so, does the level of the mission have an effect ? (Arguably, since agents will allocate missions to their own system and surrounding ones rather than those far away, if missions do have an effect, then you want a system without a station in it, and if possible with few agents in surrounding systems)
Do the presence of complexes affect the calculation ? Some systems have complexes all the time (the level 1 & 2 complexes CCP have to let people practice, and the COSMOS complexes); others get them according to another calculation.
Is there anything that players can do to attract rats to a system ? Do POSs attract them ? Does actual mining, or do they prefer unmined belts ?
If and it is a big if you could work out some of this, you would then have a means to locate two sorts of systems -- those which are more likely to have rats in thenm, for the ratters among us; and those which are less likely, and therefore ought to be safer for carebear miners [that's an unfortunate turn of phrase, I recognise, since that is what griefers do: they Mine carebears (or their tears), but I'm sure you know what I mean] -- there would be fewer NPC rats, and therefore any change in Local would signal immediate alert and possible decampment, since it would be presumed to be hostile.
What do people think ? Have I wasted my time -- is this formaula already available, on one or other of the 'help' sites ?