Abel tended a "flock", which could have included sheep, goats, and/or small cattle according to the Strongs word usage.
Yet people weren't supposed to eat meat until God gave the go-ahead to Noah, says the WTS.
The earth was totally warm before the flood according to the WTS, so tending sheep just for its wool would seem a little pointless.
It seems as if Abel would have needed to live off of Cain's crops, while he spent all his time hanging out with a pretty much useless flock. No wonder Cain was a bit surly.
What do you think?