WARNING - contains biological references that may not be suitable for the dinner table.
In one of my undergraduate biology courses, we studied the animal nutritive practice of coprophagia, which, not to be indelicate, is the consumption of feces. We know that dogs do it, exactly why is unknown.
Rabbits do it as well, by contrast we are well-versed in their motivation. Their digestive systems cannot fully process a vegetarian diet so another helping of the same food which has been "pre-processed" maximizes the nutrient uploading. It has been observed that there are two forms of solid waste from rabbits: green pellets that are re-consumed immediately; and the familiar rabbit pellets that are waste with no further food value.
To help me remember this quirk of nature, I taped the following study note to my residence room wall:
Green - good poo
Hard, brown - don't eat
Needless to say it was quite the conversation starter (or stopper) and I kept it posted long after that exam had passed.
All this to inform you that Kai has expanded his palate to include peas.