Abstract
In this paper we investigate simple eco-grammar systems with dynamically formed teams of agents. Three natural conditions for constituting a team, based on the agents' current capability of activation, are considered. We study the relations of language classes of these simple eco-grammar systems to each other and to some other well-known classes of languages. Moreover, we prove that any recursively enumerable language can be obtained as the intersection of a regular language and the language of a simple eco-grammar system where the acting teams of agents are formed according to two of the above conditions.