Nursing kittens

We have 4 kittens right now, from 2 different litters. The smaller 2 try to nurse on the larger two whenever they're feeling a little tired. It really irritates the bigger ones but they don't do much besides try to move and eventually just give up, as the smaller ones are ridiculously persistent. They will complexly soak the bellies of the larger ones while trying to nurse. Some people have told me to "gently push them away" but this is laughably ineffective. They go right back to trying to nurse with all the fervor of a cat who hasn't eaten days. What do we do?

Some people in rescue have made them little onesies out of baby socks.  The kittens are just following their instinct to nurse and being smaller, they probably ned to eat more often than the larger ones.  You might be wise to set them up in two separate incubator carriers, depending on how old they are.  Also, sooner or later if the larger ones are boys, the smaller ones will latch on to something that appears to be a nipple but isn't but still gives warm liquid, and the llarger one can get sore and raw and get a bladder infection.  Perhaps you could feed the little ones more often, and then if there are just the two of them together, they will sleep until the next feeding.  Of course if you could find a nursing mom who would take them on, that would be great.  We do that all the time in rescue.

M mussen

Some fosters will soak a corner of a piece of flannel in kitten formula, and encourage them to suckle this. If draped over a stuffed animal the kittens can even knead it while sucking.

Others soak a new makeup sponge in formula for kittens to nurse on.

Thanks for the tips. These cats are about 8 weeks old, they've been off formula for quite some time, is this still recommended?

Thanks for the reply. These kittens have been weaned for a long time, they're somewhere around 8 weeks, so they aren't actually meant to be nursing at this point. They're getting plenty to eat, I separate the smaller ones when they get their wet food so that they get enough. I am thinking it's physiological issue I don't know how to address .

Actually, it's not at all unusual for kittens who were separated from their moms too young to want to suckle while they are still young.

Giving them something to suckle redirects them from sucking on each other.