Fish suicides

Well the second week in after getting the 12 fish it seems 7 of them commited suicide by trapping themselves near heater. Of course I came to that conclusion after rushing about checking the tanks pH and temp over few time to make sure nothing went off. I burn myself doing just that and my stings. They pretty much fried to a crisp then turned into a muck paste. As for the rest one seems pregnant. It won't lay the eggs unless a male comes around. After that we should have about 3-5 days before the eggs hatch. so I'm now going to watch and see what happens. I can remove the eggs with an eye dropper or a straw. I'm off to dig for Sult 1 articles and then I'll regroup. So far I've logged 20 hours i could've stay longer then 2:00pm however security was bit rude about me sitting around in the biology room and all the public computers were busy.