You need to investigate - I had to go for a look with a torch in the middle of the night!
I did warn him though - 'if you feel someone pulling your pjs down in the middle of the night its only me having a look up your bum'
Alternatively you can look in their poos and you will see them wriggling!!!
Easyish to treat - worm tablets from the docs taken by all in the family
Then short nails, rigorous hand washing and bedding and towels and pjs washed in hot hot water.
You can give a second dose of the tablets if it still isn't clear 2 weeks later!
Isn't parenthood fabulous