
One thing you can do is create a barrier out of chicken wire. Simply plant your bulbs and cover with the depth of soil recommended for the type of bulb, then roll out a length of chicken wire that will cover your bulb bed, hammer a few lawn stakes to hold in place, then add a little mulch to cover the wire. This will help prevent rodents from accessing the bulbs. In the Springtime, remove the wire so the plants can have ample space to grow.
Bloodmeal is another option to help deter pests. You can sprinkle it in when you plant the bulb, and also sprinke some on top of the soil when done planting. Bloodmeal helps protect, as well as provide nutrients to the bulb.
Additionally, try planting bulbs that are unsavory to rodents like daffodils, snowdrops, snowflakes, allium, hyacinths, muscari, fritillaria, bearded iris, foxtail lily, squill, anemone, freesia, callas, gladiolus, ruberose, liatris, ranunculus, and cyclamen.