A friend recently lost one of her cats. She had two cats (brother and sister) for 13 years, and unfortunately had to have the male put to sleep due to illness, about three months ago. She is worried that his sister (Mindy) is missing him, and thinks that she is scared to go places that he used to go outside, and that she won't eat where he used to eat, sleep where he used to sleep etc. Is this normal cat behaviour? Years ago one of our cats went missing for a day and a half, thankfully she came back (we still don't know where she got to!), but her sister didn't show any signs of missing her, except for sniffing her a lot when she did come back. My friend has taken the loss of her cat very badly, and I'm worried that she may be imagining these things? Also, would it be a mistake for her to get another cat? She thinks that Mindy would hate it - she's very bad-tempered!