-100% unit feat?

[Solaristics]

I'm getting a unit feat of -100% in the combat odds preview window but I don't know what is causing it. It seems to be applying to all the units I'm using versus some of the planet's creatures. I thought it might be insufficient armour penetration but the hard attack number of my individual units exceed the creatures' hard defence. What am I missing here?

[Soar_Slitherine]

This is caused by the Absorption wildlife feat. To get past the Absorption, the relevant attack score, before modifiers, needs to be higher than the creature's hitpoints (not its hard defense) modified by its wildlife feats.

[zgrssd]

Defense is not Hitpoints.
It is the Damage Die they roll, when a enemy walks into their Hex and is of the proper type.

Also the Callibre calculation used for armor does not care for HP or Attack value. It only cares for comparing the MM values or equivalents.