Michael Radzichovsky (and by the way... I want to list this as a + to him, but I have no idea how to do this... suggestions would be welcomed! I just created a hyperlink to his Google + profile...) suggested doing away with the D16 altogether (and even the D20) and capping the progression at D12. Since (as I talked about two days ago) I have layered in multiples of dice, this wouldn't be too difficult of a feat to accomplish. I don't love the idea of the ants and their ilk having the potential to be as strong/quick/intuitive as a comparable predator, but it's not terrible.
Look at it this way... in an analog to 'our world', D12 body would be a bear or especially powerful crocodile. That's not over the top for what a human with maximum potential could achieve, although it's pretty close. However, what we're doing with predators is saying that you can be as strong as a big crocodile (the 'medium' predator) but not nearly as strong as a good-sized dinosaur (the 'large' predator) and nowhere in the same league as Godzilla (the 'huge' predator). You are supposed to need an army to take down Godzilla. That's the concept with the biggest of the predators - you call in your entire tank division.
Michael also brought up the problems with multiple dice exploding, and I agree that this could be an issue. I'm toying with having only a second die (instead of multiples of the same die)... so a large predator would get (for instance) an extra D6 (that could not explode) with its Body Damage and Hits rolls, while a huge predator would get an extra D12 (again, that would not explode) with its Body Damage and Hits rolls. Grenades and larger explosives could work under similar principles - a grenade always gives an extra D6 alongside its basic damage/effect, and this extra die could not explode (sorry, but the pun of exploding dice while throwing a grenade is just too much for me).
You could then rate all explosives/heavier weapons systems by their primary and secondary dice ratings - and that second die would always be a D6 (for personal or mediums-scale things) or D12 (for the big stuff), with the primary die delineating the subtler differences between a grenade launcher (maybe D8 primary + D6 bonus) vs. a mortar (maybe D12 primary + D6 bonus). In either case, only the D8 or D12 could explode, but the 6 is just taken at face value...
As a matter of fact, you could use the second die to help determine the area of effect... this really randomizes area of effect considerably (which I like to a point, but don't like to be this extreme). I was toying with diminishing damage over area, but I don't know that the level of realism/interest this brings to a fight is worth the increased time/energy spent doing the math. Here's a for instance of how this could work...
Your fragmentation grenade deals D10 (primary, can explode) + D6 (secondary, will not explode) damage. All targets within 1 cm of the grenade's detonation suffer the full wounds; each 1 cm beyond this cuts the damage in half, up to a total number of cm equal to the result of the D6 roll. If I roll 7 on the D10 and 4 on the D6, all targets within 1 cm take 11 Hits; all targets within 1-2 cm take 6 Hits; all targets within 2-3 cm take 3 Hits; all targets within 3-4 cm take 2 Hits; targets beyond 4 cm take no damage.
However, if you roll 10 on the D10 (exploding) +8 on the second roll, +2 on the D6, you have a grenade that deals 20 Hits to all creatures within 1 cm; 10 Hits to all creatures within 1-2 cm, and no damage to creatures beyond 2 cm.
This feels weird... I don't mind (in fact, I like) that damage diminishes over a wider area of effect. Maybe just say that it goes halves automatically until you get to 5 or less, and then it's done. A grenade dealing 14 Hits deals 14 for 1 cm, 7 for the next, and 4 for the last, then it's done. This is easier to remember, but doesn't necessarily rely on the second die to set the area of effect - the total damage does that for you.
Hmmm. This ended up being F + G(renades), but I'll still give you a new G entry on Monday anyway!