The space between the eyes

[mark83]

I was hoping to get some clarification on the rule about food being no longer(or was it wider?) than the space between the eyes.

Is this like a concrete rule or just a guesstimate? I'm feeding dubia and just want some more guidance because I've heard horror stories about beardies dying from being fed insects that are too big for them.

Thanks.

 

[Livey]

Its usually a Rule to follow,
but roaches iv heard it can be sometimes the width instead on length?
but im not very sure on that..