A “Double” fear effect in a tri-trophic food chain model Harendra Verma, Kwadwo Antwi-Fordjour, Mainul Hossain, Nikhil Pal, Rana D. Parshad and Pankaj Mathur Eur. Phys. J. Plus, 136 9 (2021) 905 Published online: 03 September 2021 DOI: 10.1140/epjp/s13360-021-01900-3