Heard scratching in the attic. Set 2 traps, caught 2 mice.

[bobcat]

Not idea how they got there, but I thought I would find out when they typically give birth. I was not prepared for the answer.
Check this out:

Female house mice have very short pregnancies, so they give birth frequently and quickly.

Gestation (pregnancy) length​

• Mice are pregnant for 19–21 days.

How often they give birth​

• A female mouse can have up to 10–15 litters per year.
• They can even become pregnant again within 24 hours after giving birth.

Litter size​

• Typical litters contain 5–12 babies (pups). (That's conservatively 80 per year)

When mice start reproducing​

• Females can start having babies as early as 6–8 weeks old

 

[Jules]

Put out a few more traps, just in case. If necessary, sell the house. I hate mice.

 

[oscash]

We often had to put rat bates up in the roof cavity. Apparently, they eat the bate and go off looking for water because they dry up. Nothing worse than hearing crunching away in the roof late at night.