No, it's supposed to be poisonous to them. Not sure if this will help:
SAFE PLANTS
Broccoli, Beetroot (Not the leaves), carrots, carrot tops, parsnips, Swedes, turnips, cabbage, cauliflower, cauliflower leaves, banana, banana skins, celery, celery tops, Chinese leaves, cucumber, parsley, peas, spinach, watercress, apples and pears (without the pips), melons, agrimony, avens, chickweed, clover, coltsfoot, comfrey, cow parsley, dandelion (in small quantities as it is a natural laxative), goatsbeard, groundsel, goosegrass, hawkweed, mallow, meadowsweet, nipplewort, plantains, shepherds purse, sow thistles, trefoils, vetches, yarrow and lettuce (only in small amounts as it is a natural diuretic).
UNSAFE FOODS
Any plants that are grown from a bulb, all evergreen trees and shrubs, anenome, bracken, bryony, buttercup, celandine, charlock, convulvus, deadly nightshade, dogs/herb mercury, foxglove, hellebore, hemlock, henbane, horsetails, ivy, laburnum, lily of the valley, mayweed, milkweed, monkshood, meadow saffron, wild and beaked parsley, poppy, privet, ragwort, rhodedendron, rhubarb, scarlet pimpernel, snowberry, spurges, toadflax, travellors joy, yew and most docks. Certain docks can be fed but it is so difficult to tell them apart it is best to omit them altogether.
ARGUABLE FOODS
There are some foods that are arguable as to whether they are safe, or even healthy for our little friends. A couple of these are Tomatoes and Potatoes. We would suggest if you do feed these, that it is in small quantities and not to often.