Thank you for your query,
Toddlers usually cant describe their headache, but they become irritable,cranky ,or vomit or prefer dark rooms to sleep.
As your child is having headache look for any causes of headache like cold
, infections of head and neck and observe his vision by seeing his preference for near and far objects.
Consult your Pediatrician
to look for the causes of headache and for its management.
Hope i have answered your query.