Previous research indicates that complex biological concepts may be successfully introduced in preschool age, provided that suitable educational interventions are designed for the initial stages of education. In this regard, there is evidence that a basic understanding of the issue of the ecological interactions among organisms may be achieved in the preschool years. With this in mind, this research project tests the assumption that recognising the fact that plants and animals are not isolated creatures, but live engaged in constant interactions in nature, may begin to be understood in early education. To that end, this study examines the content of free drawings that a sample of 328 children aged four to seven years of age, undertook when explaining their understanding of plant life. Data regarding the type and frequency of the depictions of animals found in the children's graphic explanations on flora is collected and read in conjunction with participants' gender and academic level. The results show that a substantial proportion of the children in the sample spontaneously drew illustrations of animals in their graphic explanations concerning vegetable life and, more significantly, some pictures show plants and animals engaged in clear contact. This is the case, despite the fact that the drawing activity had been focused solely on the issue of plant life and no indication linked to depicting other kinds of living things mentioned during the activity. The conclusions discuss the data collected in connection with the growing number of research projects that study the question of how young children begin to embrace the fundamental biological concepts that pave the way to the understanding of natural phenomena and make the public capable of making responsible choices when it comes to sustainability issues.