This song is really common, in Peru too.

Yep, it's very common here in Guatemala too. I would say I've noticed children born in the last 10 to 15 years don't know it as well as older generations, but it's still very well known.

Los pollitos dicen  Pío pío pío  Cuando tienen hambre  Y cuando tienen frio La gallina busca  El maíz y el trigo  Les da la comida  Y les presta abrigo Bajos sus dos alas  Acurrucaditos  Duermen los pollitos  Hasta el otro día Cuando se despiertan Dicen "mamcita, Tengo mucha hambre Dame lombricitas

Very common, I'm puertorican and it's a very popular song in kindergarten and other elementary grades throughout Latin America. :)