First time we witnessed a kill in the back yard, the kids freaked out, especially when the hawk sat on a tree limb and meticulously plucked all the feathers from the luckless house finch. I tried to explain to them it's all part of Nature (great circle of life and all that), but they were 6 and 4 at the time and didn't see it that way. As time passed, they'd still say "ick" on occasion, but they also learned to appreciate the skill involved (since the hawks were only successful about 20% of the time).

Regards,
Scott