ball python first feed tips please :)

[SRMD]

I will check tonight. I've read that they should be completely round but then others say slightly triangular. He was the thickest of the two youngsters they had. I'm still trying to get his temps right so I've been faffing with the tank all week which isn't helping his stress levels. It was too hot yesterday I'm still waiting for my thermostat in the post.

In my opinion, you should sort his set-up out.. also if you haven't got a thermostat I would regularly check the temps to see if they are ok.
Once you have sorted everything out I think you should leave it a week let him settle in before you feed him.
Once you weigh him, his weight divided by either 0.10 or 0.15.. (for example: 520*0.10/0.15 = 52/78) and that is the rodents weight size you should be feeding your BP. (this only applies to hatchling and juvenile BPs under 500g)

Hopefully this makes sense I'm a bit rusty with information.