Girls, hello! Can you tell me what it could be? The baby is active and…

Girls, hello! Can you tell me what it could be? The baby is active and cheerful, he pulls all toys and even diapers into his mouth, chews. But he sleeps without a breast completely... He cries, turns over, searches... Why is that? The gums aren't swollen... He was scared of something, so he's sleeping badly or teething?