My kittens are about 5 weeks old and the mother is still taking very good care of them. Although sometimes when she thinks its time for a cleaning she will grab ahold of them pretty roughly and kick with her back legs. She doesn't always do this but sometimes she does. WHen she does the kittens will cry and i feel like i should step in. So I have been. But i am not always here. And also she cleans their butts and takes care of their waste which is nice so there won't be any accidents I have been actively trying to get the kittens litter trained so that the mom will no longer need to feel the need to clean them so actively. Is this normal behavior of a mother cat, or should i continue to step in when this is happening. It doesn't seem like she is actually hurting them but the kittens just dont like it.