peck at
To eat something at a slow, unenthusiastic pace in very small bites. I wonder if Mary isn't feeling well—she only pecked at her dinner. He sat moodily at the table, pecking at the plate of vegetables his parent put in front of him.
peck at something
1. Lit. [for a bird] to poke someone or something with its beak. The bird pecked at the ground, snatching up the ants. I tried to hold on to the bird but it pecked at me hard.
2. Fig. [for someone] to eat just a little bit of something, being as picky as a bird. Are you well, Betty? You are just pecking at your food. Please don't peck at your food. You should eat everything.
peck at
v. To eat something unenthusiastically by taking small bites: The sullen child only pecked at his carrots.