The latest addition to the family is - 3 guppies - which our little one got from her class when she "graduated" from Kindergarten. For the new members with a combined net worth of 50c, we had to shell out ~25$ for tank, fish food etc etc.
One evening, our daughter was looking inside the tank "The guppies are eating". I lamented, that's all they do 24/7. Suddenly she recollected an important thing from her own swimming lessons - "But they should not eat and swim. They will throw up. That's what our teacher told". It took me while to convince her that they swim and we walk. We shouldn't eat and swim. But they can. What they shouldn't do is eat and walk like we do. Then they will throw up ! The laughter burst from her thinking about "walking fishes" was well worth the effort of the onerous weekly tank cleaning task!