Male Mollies/ Male Platys

[Rinyfish]

Hey!
I'm very new to the fish world and I have a few questions.
I have a 40L tank and in it I have 4 Male Mollies and 3 Platys.
Ever since I introduced my Platys to the tank my Mollies have begun chasing each other around and what looks like nipping at the belly's.... is this normal? Also I dont have what i have read to be a 'crowded' tank as i only have a log for them to hid in and a fake plant.
Any help will do!! Thanks in advance

 

[fluttermoth]

Hi there, welcome to the forum.

What sex are the platies? All livebearer males will try and mate with, and fight over, other livebearers, even of a different species.

Overcrowding, when we're talking about fish tanks refers to the amount of fish you have in the tank, not the decorations.

In fact you can't really have too many decorations, especially plants, as fish feel much safer and will behave more naturally, if there are a lot of plants to hide in. A very open tank means that the weaker fish can never get out of sight of the stronger ones, and any bullying gets much worse. Neither mollies or platies live in, or hide in caves, in nature, so your log isn't going to be very useful.

I'm afraid, in the long term, both mollies and platies grow too large to live happy healthy lives in a 40l tank.

 

[Rinyfish]

All my fish are male. Mainly because my new to this I dont want fry until I can understand thing more clearly. The platys are still small but my mollies are fully grown.
Is that what the chasing is, just fighting? They dont bother the platys at all as they are super chilled out.
My mollies go I the log thing all the time, sometimes there is two in there. I'm planning on getting another plant as the platys tend to chill in the one I already have.

 

[Byron]

Mollies will attain 3 inches for males, with females 5 inches and some getting to six inches. Even if you have only males, four of them are crowded in a 40 liter (10 gallon) tank. The platy males can attain 2 inches (females 3 inches).

Welcome to TFF.

 

[Colin_T]

They are fighting over territory and dominance. It is preferable to only keep once species of livebearer per tank.