Mouse/baby rat....

Mice can get through the tiniest of holes.

If it was a rat it might have simply walked through your open door.

Rats are easier to deal with than mice in my experience.

Hope get it sorted

I suspect I have a mouse because I heard a squeaky sound either coming from the garden outside or the kitchen. What are the tell tale signs of a visitor. I have not seen any droppings.

I have not seen any droppings - just the culprit itself! No nibblings at flour or cereal bags etc. as one might expect. I suspect it did just wander in as we have had several doors to the outside open in the sunny weather.

The usual telltale sign is the smell of mouse urine.

Luckygirl wrote
"The usual telltale sign is the smell of mouse urine."
Exactly - you can't mistake it.
When we lived in the country we once returned after 2 weeks away and the whole house stank.
We resorted to poison too.

Do you live in a rural area? We lived by a farm at one time, and we would get little field mice running in. They are so sweet, but sadly they had to go, we always used traps

We used traps , poison , neighbours cat , but got Rodent Control man , we had him every autumn , but not this time of year . We moved house and no wee visitors . The cat was pretty good btw

I had one of more in my kitchen last year.
I bought some stuff from Amazon called something like, big blue cheese.
You put it in a container with holes each end and the mouse or rat nibbles at the block and then goes away to die.
It worked.
I now have a cat!!

The cat that adopted us has a habit of bringing live field mice/wood mice/shrews in in the middle of the night and letting them loose in our bedroom (the door is open to stop cats shredding the carpet trying to get in). It's great fun trying to catch them with a box - put it over them and slide something flat underneath. But then it's a walk down the road in my nightie to get rid of them over the churchyard wall. If we don't catch them straight away then we have a humane trap which we bait with peanuts - works really well. Of course, if it was house mice, they'd get shorter shrift. We have some of those deterrent gadgets which seem to have had some effect on them (they come in from the seldom occupied house next door).

We had mice in the loft, they were getting in through the weep holes between the bricks and climbing up the cavity, we managed to buy the little plastic grills that the builders are supposed to put in the weep holes.
Mice can get in a hole the size of a pencil.
We had to use old fashioned mouse traps baited with high cocoa content dark chocolate, we eventually trapped 13.

You can usually tell a rat (even a baby one) by the size of its tail, which is much thicker than a mouse tail. Both types of rodent leave wee everywhere they go. One of the worst smells is when a rat has died in the eaves or under the boards or in the wall and it can't be mistaken for anything else.

It is no more! I put down a trap yesterday night and caught it within 5 minutes - I heard the trap spring as I left the room after setting it!

I did not use a humane trap as my experience of those is that the poor creature gets trapped for hours in a state of terror. Better I feel a quick end and off into the field behind us to feed the buzzards that circle overhead. Part of the cycle of nature.

We used a humane trap and released the mouse a few miles away only to be told that it would probably die or be killed by other mice anyway.

They seem to prefer peanut butter to cheese so we used that in the trap.

It’s a horrible business but you really don’t have much choice

It is horrible, I agree, but they have to be dealt with. I'm with you Lucky in your choice of trap. Using any kind of poisoned bait for them to nibble and 'go away to die' means they can end up outside somewhere for another creature (often an owl) to eat and therefore be unwittingly poisoned in the process.

Far better to kill quickly and cleanly and leave the unpoisoned body for an owl to enjoy.

Rats are easier to deal with than mice in my experience

Mine too, but they take you to very nice hotels.