No more babies

I was producing more then enough babies for my snakes up intill the last month or so. All i've recently is two litters of like 6 born...
Watch happened to my breeding? It was pretty consistent before and i was swimming in rats.. I have 1 male to 6 females in 3-4 tubs on my rat rack (huge huge cement tubs) I keep the watered with multiple water bottles per tub...
Their in my second bedroom so i dont think temp is the problem...
I've been short on food lately as it took my feed place (the only one in town that carries mazuri in bulk) 3 weeks to get my shipment b/c for some reason mazuri or someone kept zeroing out my order...bah...not happy about that...but ive been buying the 2 dollar boxes at walmart to tide them over (costing a ton cause each tub goes through a box in like 2-3 days....)
I'm wondering if its over populations but their tubs our flipping huge...Has anyone else had this problem? Could change of food hurt there breeding?
I went ahead and retired some males also...
Kinda sucks cause i think this means im going to have to start buying again till im full production. I just ran out of my grow outs so im going to have to let the new babies grow to start a cycle like i had before..
So please tell me any tips or personal experience yall have that could help me out.. :D thank you

When production stops, Replace the females.

I re do groups ever 7 months with new females and ever 12 months with new male

One of my casual observations with rodents is that success with breeding groups is hit or miss. I have thrown together a male with females and 22 days later all of the females have litters. I had other groups that were together for two months and nothing.

Now I change things up quickly if I don't see breeding or if the litters are small. That's why you need replacement males and females available or production stops. Move the females to another male for one last shot. If you get the same results just retire them and move on.

Sound like you females have been bred out. time to replace the females.

^^ Im no expert... But when the numbers go down its time to put someone younger in there for him...