This study analysed the characteristics that children in the initial stages of schooling attribute to living beings. Interviews were conducted with 138 children aged 3-7 years in a school in the Spanish city of A Coruña, Galicia. Aspects found in pen-and-paper activities dealing with living beings, provided by the teachers (158 in total) at this school, were also analysed. The findings show that the children recognised that humans/animals are alive, but the youngest ones in particular did not recognise that plants are alive. The children used morphological and functional aspects to explain that the different specimens are alive, although they had difficulties using the same characteristics for humans/animals and plants. The activities provided by the teachers were aimed more at identifying specific specimens than at studying the key ideas that characterise living beings in general. The paper also discusses the fact that these activities do not make it easier for the pupils to acquire a unified or accurate concept of what a living being is.