towards the other, why? I have a 20 gallon tank
1 female swordtail
1 male swordtail
(had them about a month)

1 female silver molly
1 female black lyretail molly

(have had them for about 2 weeks)

The silver molly chases the black molly alot (even though she is bigger) and nips at her here and there. I thought she only chased the black one if she got close but sometimes when they are at opposite ends she will charge to the other end and chase her. The black molly never chases the silver molly back. and the silver molly never chases any other fish.