What is eating my young citrus leaves ? I can’t find any bugs or trace of them.

Hi Dominque, it could be the leaf roller caterpillar. These chew leaves, then roll up the leaves to form a cocoon. If you can't spot any of these, it could be the grass grub beetle, these fly at night and are hard to spot. Use a natural insect spray to control - check at your local garden centre for options.