According to a comment in the original post, majority of commercial ones do not contain insects:
"Only some kinds of figs (so called 'Smyrna' types) are pollenated by wasps. The vast majority of figs eaten come from varieties that produce fruit parthenocarpically. It is highly unlikely that the fig you ate at the supermarket was of a variety pollenated by wasps: most north american commercial figs are not."
I chose to believe this explanation :)
Essentially a mutation that gets trees to produce useless fruits that don't have actually developed seeds and don't need pollination. While that sort of mutation would normally be selected against, since the trees can't reproduce via seeds and are expending energy on producing fruit for no reason, it's deliberately selected for by farmers who artificially reproduce the trees via planting cuttings, or grafting them onto rootstock.
(Though I guess really the "naturally" versus "artificially" distinction is a bit, erm, artificial, if you just think of humans as another species, since lots of natural selection is influenced by relationships between species, like the wasp-fig relationship in this article. So trees evolving to please humans isn't really different in kind from trees evolving to work well with wasps.)
"Aritificial" means "man-made", and is a (man-made/artificial) word invented to describe things that are done by humans, not other animals. By definition, everything a farmer makes is artificial.
Personally, I find this set of words (artificial, unnatural, etc) to have way, way too much baggage, so I prefer to just define them as nonsensical (i.e. it's impossible to do anything unnatural) rather than assume that they are useful tools for communication like other words (since most people will have varying definitions of what is unnatural, which aren't rationally guessable).
Holding this line of thought also allows to instantly come across as an annoying smart-arse in parties (and online too, I suppose).
Here is a great article with more details :)
There is an amazing amount of wildlife in a wasp pollinated fig. If you break one open, all sorts of interesting stuff crawls out, not just immature wasps, but also a lot of organisms that prey on the wasps.
err, that's what I was most interested in... I've eaten an entire pack of fig newtons in one sitting.
Glad I don't like fig newtons. :)
Tastes like ... victory.