I have a guppie that i got it about 2 days ago and 1st day was ok but now she does not want to eat and no activity at all. I saw that someone from my tank nipped her tail and thought to put her in the breeder so that no one will try to nip her. I still left her in the main tank though. What could be the problem. I do not think that she is due because her belly is not so big. Also she is always on the top of the tank.
Also, guppies are slow swimmers so almost any other fish will nip at them.
It is perfectly normal for a fish not to eat for a few days. If it continues, get some garlic powder from your kitchen cupboard and mix it with a cup of water from your tank. Pour it into the tank and then feed about 20 minutes later. Hunger strike over.