There's a rat shaped hole in my life.

Ni, my daughter's rat, has just passed on to join his brother in the sky. Don't try and read anything into the phraseology of that statement – it's just a cliché to let you know that I had him put down this afternoon. But that sounds so cold and uncaring. In fact, it was a decision that was probably 24 hours overdue and had caused much heartache. But that time gave us a final chance to chat and re-assure each other. And I don't mean talking to my daughter, she's away at Uni these days, but with Ni.

Like so many fancy rats, he developed a tumour. It is part of their heritage, as they are descended from lab rats, who were explicitly bred to be susceptible to cancer. The truly amazing fact is that Ni survived over two months with a growth that ended up as large as his head. And, until the last two or three days, he lived a bright and happy life.

His brother had succumbed to a weak heart some 6 month previously, so Ni relied on contact with us. This was problematical at first, as Ichi has been the dominant rat and Ni was shy, declining to be removed from his cage. But he learned to trust us and would come out most nights, when Karen or I fed and cleaned him. He often came out for longer periods, too, and wasn't seriously adverse to being bathed. In fact, he was meticulous about being clean. And when Karen wasn't at home, I gave him his daily chocolate treat during early morning chats as I got up.

And Ni was remarkable in that he could read you mood. Now, I'm aware that the sceptical amongst you will say that I was anthropomorphising. But, more likely, he was using animal instincts to ensure he stayed out of trouble. If I was short tempered he would stay out of the way. But oddly enough he was most likely to want a chat on days I was sad or lonely.

Now he's gone. Tonight I will not have to select some fresh fruit or vegetable to add to his dried feed. His cage, which was just beginning to rust, is in a skip; the bits and pieces that were his living room, bed and toys are all cleaned and packed up. No one will nuzzle my face or clean my hands. I shall miss him.

There will be new rats in the house and this time they will be mine. But not yet. It is time to grieve for Ichi and Ni. In the new year I shall be looking for some kittens and a new cage.