Tenant requesting installation of rabbit proof fence

[Luciano Suehara]

I have a great tenant but he is complaining about rabbits burning his backyard lawn and pooping all over the place. He is saying that the gap between the fence and the ground is too high (3-4 in), allowing the rabbits to easily access the backyard. So he asked me to cover it (can use a steel net, fence extension, etc). This is not in the contract and wonder if this is my responsability or not. Any experience on that? Thanks in advance