biting their nails (idiom) - to be very nervous, as someone who bites their fingernails (เล็บมือ) because they are very excited or anxious - กัดเล็บเพราะมีความกังวล
biting their nails (idiom) - to be very nervous, as someone who bites their fingernails (เล็บมือ) because they are very excited or anxious - กัดเล็บเพราะมีความกังวล