In this paper we study fuzzy differential equations with uncertain parameters modeled by interactive fuzzy numbers. The interactivity is formalized with the help of upper semicontinuous t-norms. To obtain solutions to fuzzy differential equations we use two different approaches. The first uses a family of differential inclusions while the second is the fuzzification of the deterministic problem using the Zadeh extension principle. We show that the solutions obtained by the two methods are equal. Interactivity among the parameters and variable of the problem are studies with respect two methods. We show that a hierarchy in uncertainties of the solutions arises when we chose one of the basic t-norm (the minimum, the t-norm of the product, the t-norm of Lukasiewicz and t-norm of the drastic product) to model the interaction between parameters. Finally, to illustrate the concepts introduced in the paper, we study the Malthusian model with interactive parameters Ver menos