The recent discovered iron pnictide superconductor which shows a transition temperature up to 50K has drawn much attention in the community. There are indications that superconductivity in the iron arsenides family may be driven by a magnetic pairing mechanism, the nature of which remains poorly understood. In our recent unpublished experiment on optimal doped BaFe1.9Ni0.1As2, spin excitations were observed from 5 meV up to 300 meV, and transfers from tetragonal (0.5,0.5,L) to (1,0,L) as the scattering enters energy transfer of 150 meV. The natural next question would be how the high energy spin excitations change in the overdoped regime, where the system becomes more metallic and Fermi-liquid-like. This experiment successfully, will complete the picture of how spin excitations evolve when the system evolves from non-superconducting to optimal-superconducting and over-superconducting.