I have to say that Smidgen, when he arrived was 16 weeks old, and had no compuntion whatsoever about suckling from Esther, me rescue cat who had recently been spayed having weaned the last of her own kittens, they had quite the family thing going until I realised what he was doing (the little horro!). Once Esther realised i was on her side it soon stopped, but he was more than happy to take advantage while he had the chance ..........