Back in 1997, when they were popular, they were banned at my school and nobody liked me so they would've told on me for having one in class. I brought three different virtual pets to school every day. (A Dinkie Dino, a Digital Doggie Giga Pet, and a Nano Kitty.) Here is how I did it:
1. I turned the sound off on the Nano and the Giga Pet. I couldn't figure out how to turn the sound off on the Dinkie Dino, so I took a whole bunch of toilet paper and taped it to the back so that nobody would hear it. I tested it to make sure that it couldn't be heard, and it couldn't.
2. I wore a jacket thing every day with two pockets that zipped up. I was allowed to wear it in class because I wore it underneath my real jacket and told the teacher that I didn't think of it as a jacket. It was long, so I could put one of my pets in my pants pocket and nobody would notice the bulge. The other two went in the jacket pockets, and I zipped them up to make sure that they couldn't fall out.
3. I went into the bathroom before school started, and made sure that they were okay. Then, I put the Giga Pet to sleep. At Recess, I'd either hide in the bathroom and play with them (it was only 15 minutes long), or I'd go to a secluded part of the playground where nobody could find me, but that was risky. At lunch, I'd sometimes hide in the bathroom the whole time. (Hey, I was a loser without very many friends... The playground was stupid and people threw things at me and called me names.) Usually I'd just go in there once at the beginning of lunch and once five minutes before the bell rang. I'd put them all to sleep at the end of lunch. After school, I'd go to the bathroom and check on them before going home. I walked home, and people would tell on me if they saw me walking home with them. Once I was at home, I played with them like normal.
4. Don't tell anybody that you have them at school. People can't be trusted to be quiet. They might not mean to hurt you, but a lot of people have really big, loud, stupid mouths. I made the mistake of telling my best friend, and she almost got me caught several times. I had to have a very long talk with her. Hehe.
5. Most importantly, don't do anything stupid like checking on them in class. Even if you're watching a movie. It's a very good way to get caught, and you do not want that. If you really feel the need to check on them, ask if you can go to the bathroom. I recommend doing this only once every two days at the most, or else the teacher will get suspicious. You have to be smart and sneaky or else you will be caught. Don't pull it out in the middle of the class because there are probably a lot of mean kids who think it is funny to get other people in trouble.
One time, I accidently left the sound on on my Digital Doggie, and I got caught. I didn't want it to die, so I faked sick and the teacher had to give it back to me before I went home. He told me not to bring it again. Little did he know that I brought it every single day after that.
If you have any questions, be sure to ask me. I was a very sneaky little kid.