Disapearing Guppy

Question
Hi, I have a question about locating fish.  I have two albino corys, and had three full grown guppies (one male two female) in a 10 gallon tank.

Yesterday I was watching my fish swimming about and I noticed that I was down one guppy that had been there when they were fed that morning.  I searched the tank for her, checked outside the tank (the top is all closed up so she couldn't have jumped out), took a look inside the filter and finally picked up all the ornaments and checked around the plants.

All I found was a tiny fry and some sort of grass-like algae growing on an ornament.

This isn't the first time a fish has simply vanished without a trace either, it's happened before when I also had tetras (never found them).  There are no skeletons, no remains, I don't have an animal in the house that can get on the counter, open the top of the tank and get to the fish or for the fish to get out, unless they've learned how to apparate.

Is this normal or have you heard of fish just vanishing before?  This has been frustrating me since I started keeping fish four years ago.  I'm totally clueless.

Answer
Rebekah,
Unfortunately, I hear about this a lot. For whatever reason fish disappear from the tank only to reappear days later. Even if you tear the tank apart looking for them. Sometimes they just vanish and we have no idea why or how. If you have a pleco in the tank, some people say they can get rid of a fish very quickly. I wouldn't say it is normal but it does happen often. Wish I could help you out better but sometimes even us experts don't have the answer.