I come downstairs to find a large black rat staring up at me from the middle of the kitchen floor. The rat, which belongs to the oldest one, is plastic, and once briefly served as a prop in a Whitehall protest about waste disposal preparations in the event of a no-deal Brexit. But that doesn’t make our early morning encounters any less alarming. My bare feet briefly leave the floor, every time.

The rat can turn up anywhere, because the dog has adopted it as a sort of playmate. As a result of the dog’s devotion, the rat is also now missing the front half of its face.

“I’m not sure how many more random rat sightings I have left in me,” I say later that evening. The dog is crouched on the sitting room rug, gently gnawing the rat’s head.

“It’s surprisingly realistic,” says the oldest one.

“It’s worse than realistic,” I say. “Every morning there’s less face.”

“Is that your rat?” my wife says in her talking-to-the-dog voice. The dog puts a protective paw on top of the rat’s scaly tail.

“It’s difficult now it’s darker in the mornings,” I say. “The tortoise leapt out at me the other day.”

“Leapt out?” the middle one says.

“People think tortoises are incapable of surprise,” I say. “But they’re wrong.”

“Maybe we could get a new one with a face,” my wife says.

“I’m sure I can,” the oldest one says. “We had loads of them. They cost a pound each.”

“That’s what we need,” I say. “More rats.”

The next morning I find the rat at the foot of the stairs, lying upside down on the tiles.

“Morning,” I say, stepping over it. As I approach the kitchen, the cat fires itself through the flap.

“Miaow,” it says.

“Don’t start,” I say.

“Miaow,” the cat says. I open the cupboard.

“There’s no cat food,” I say.

“Miaow,” the cat says.

“I can’t go to the shops now,” I say. “Look at my hair.”

“Miaow,” the cat says.

“Also, there’s still food in your bowl,” I say. “And also, shut up.”

I look across the kitchen and see the tortoise standing in a thin sliver of sunlight, where only a moment before he was not.

“Why are you even in here?” I say. “It’s meant to be nice today.” I open the garden door and place the tortoise on the back step. I make coffee and carry it across the damp grass to my office shed. As I approach, the vines in the raised bed begin to shudder violently. The squirrel – my enemy – jumps out from the leaves and lands on the grass in front of me, a cherry tomato in its mouth. Coffee splashes out of my cup on to my sleeve.

“You bastard,” I say. I chase the squirrel across the garden, until he runs up a tree trunk. It’s not about the tomato – there’s a glut – it’s about maintaining my fragile status as a deterrent.

It occurs to me, I have enough problems with actual animals without having to worry about a plastic rodent with no face. I am reminded there is a perfectly real rat living in the drain by the side of the house. The cat watches me sitting at my computer through the glass door. Whenever I look over, it mouths the word “miaow”.

A week later, I awake in the dark to the sound of cold rain on the roof. The cat appears.

“Miaow,” it says.

“It’s the middle of the night,” I say. But according to my phone, it’s time to get up.

I walk down the stairs with the cat threading itself around my ankles. I flick on the kitchen light to find the rat poised on the kitchen table, turning towards me as if in surprise, staring facelessly through some kind of cybernetic eyeball.

“Jesus!” I shout.

“Miaow,” the cat says.

Closer inspection reveals that the eyeball is actually the partially exposed mechanism that causes the rat to squeak when bitten down upon, a main component of the dog’s attraction to it. I try to imagine who would leave the rat on the table, just to scare me. Then I remember that I put it there, precisely so it wouldn’t