nighttime noises

It's been a strange few days -- the weather is warming up, so there are far more people in the park. That also means we have had more visitors to our door -- yesterday one at 5am asking if our house was a "safe" house ??  I have just started to get used to the creaking of this house, the new night noises. We had a lizard in the kitchen a few days ago. Sometimes the noises are just noises... other times I am fairly certain there are animals in the walls.