Has it ever happened to you not to recognize someone you know closely? Well, that sounds a bit intriguing since not recognizing someone who's very familiar to you can't be caused by something you're used to. Of course, it may happen if you aren't wearing you glasses, or the person has just visited a hair-dresser, or is wearing some extreme makeup, but none of these ideas count when it comes to animals. However, these kittens still do have certain problems recognizing their mum. How so?