Here are some examples of how it could be used:
* "As pestinhas estão a brincar no jardim." (The little pests are playing in the garden.)
* "As pestinhas não param de me fazer perguntas." (The little pests don't stop asking me questions.)
* "As pestinhas são tão engraçadas!" (The little pests are so funny!)
It's important to note that "as pestinhas" is usually used for children or animals, but it can also be used for adults in a lighthearted way.