its the "how long is a piece of string question", last year the ferts in the court, successfully raised a litter of around 12 kitts, with a mixture of intact hobs, castrated hob and jills, this year the court has 5 jills and the castrated hob in, a unplanned litter was left alone in there, and within 3 days the kitts had been eaten, so Id say, unless your really sure of your jills, or have available cage space, and want kitts, then split them, just to be on the safe side