The large diffusion of wireless networks in houses and public environments, as well as the emerging use of VoIP phones, has entailed the need of new bio-experiments around the frequency of 2450 MHz. In this letter, a loop antenna for localized exposure of the head of small animals is designed, fabricated, and measured. The antenna design and optimization were performed theoretically and with numerical simulations. The optimized antenna was fabricated and experimentally characterized in terms of radiation diagrams and specific absorption rate (SAR) distribution inside a cubic phantom filled with an equivalent biological medium. An excellent agreement of SAR statistics on 10 g between simulation and measurement was found with an optimum SAR homogeneity (near 90%) and an efficiency value higher than 9 W/kg/W.