@fc3srx713b: The point here is that its done intentionally - for amusing or say "scientifical"-interest. And I really don't see any sense in feeding a fish to a nepenthes.
@MrAga: Any literature tells u that prey like a bird or a rat are exceptions for nepenthes, so there is no need to feed such animals! What results do you expect? Do you really think you will see a big difference in growth?
Such a carelessness makes me angry.