Never really worked with them, at least not enough to know the answer to your question.
The “locals”, however, often offered to share, but:
One time during the monsoon, we found a series of mounds, maybe 10–15 feet diameter, that were above the “flood” of the rains, and got on them to not be in the water (I later heard they were burial mounds or graves).
As we were “relaxing”, we could see some locals go mound to mound in their sampans, jump onto the mound and beat the heck out of something. As they came past us, we could see they had a pile of dead rats in the front of the “boat”. They said “chop chop” (slang for food or chow) and gladly offered to share. We politely declined.
Similar situation, but night. I was a squad leader and not my time for watch. We were pulling “ambush” duty. I was awakened by one of my men who said, “Sarge, there is something out there”. He was right.
In the water and darkness about 75 yards away was a slow moving light of some kind. We were in a night curfew zone - anything out there was fair game, no questions asked. I could have had the whole squad go rock-n-roll for 2–3 magazines. Could not see a “target” but the light was obvious.
It could have been a trap, but our experience leading up to that moment let me decide that an “investigation” was likely safe. However, I put the whole squad, quietly on full alert, made sure the Claymore detonator switches were in hand.
I took along 2 other men to “investigate” leaving the rest of the squad to cover us. We waded out to the light to discover a local (if you imagine the classic image of an old, bent over, gray-bearded Chinese peasant, that was what we encountered).
It seems he was out “night fishing”. He would hold the light over the water, and then, after a time, plunge a bottomless basket into the water, and then reach in to gather whatever had been trapped. Even though I had no fondness for C-rats, there is no way I would have put whatever he was getting into my mouth. The guy was simply trying to find food for himself and/or his family and was no threat to me or my men.
With aggressive but polite “sign language” we indicated he should get the hell out of there, now. He left quickly, probably never realizing how close to death he had been.
I never knew what he dredged up.