  Interaction among the qubits are basis to many quantum logic operations. We
report how such inter-qubit interactions can lead to new features, in the form
of bright and dark periods in the entanglement dynamics of two qubits subject
to environmental perturbations. These features are seen to be precursors to the
well known phenomenon of sudden death of entanglement [Yu $&$ Eberly, Phys.
Rev. Lett. {\bf 93}, 140404 (2004)] for noninteracting qubits. Further we find
that the generation of bright and dark periods are generic and occur for wide
varieties of the models of environment. We present explicit results for two
popular models.
