Ummmmmm...

[K.J.]

Okay, so today I got a tank divider for my 10g. Whatever they sell at Petsmart. Fit pretty well - there was a gap in the side about a millimetre wide. I put the male and female - Candi and Scragglypuss - in, and I definitely remember which side they were on because Scrags builds bubblenests, and I wanted him in the calmer non filtered side. I go to the beach for 45 minutes... and when I come back, Candi is in the calm side, Scraggly is in the filtered one. HUH?! How did they switch sides? Neither of them have ANY fin damage, so I am mystified... There's a small gap on the bottom, but the betta would have to rake it's fins against the plastic edge and go sideways, and I'm sure Candi wouldn't do that because she's eggy, and they both switched sides. They might have jumped but there's only a centimeter gap at the top. Uhhhhh....

 

[Amunet]

They'll find any opening they can and will squeeze through.
I divided my 10gal 3 ways, and one of the girls ALWAYS found some opening near the bottom that I missed and would ALWAYS find her way to the other side. It never caused her fin damage either.

I would just make sure to fill in those gaps as best you can and to definitely make sure that they're not able to jump over.

 

[doresy]

I'd deffo say it's a jumper

Long before I knew what I know now I had a betta in my community tank. In there I had a breeding trap full of molly fry. It floated a full 15mm clear of the water surface yet by the morning he was in there leaving just 3 traumatised fry Needless to say the betta died shortly after

Thankfully things have changed now but I do know that they will do ANYTHING to get at food, especially live food. They also should change that well known saying 'curiosity killed the cat' it should be 'curiosity killed the betta'