Female lycosids carry their egg sacs on their spinnerets until spiderlings emerge but spiders are occasionally found carrying shells, dirt, or other objects on their spinnerets, suggesting recognition errors can occur. We investigated some proximate cues that may influence egg sac recognition and discrimination in the wolf spider Pardosa milvina (Hentz 1844). We tested the ability of female P. milvina to discriminate among egg sacs based on size, texture, and contrast. We also tested the ability of P. milvina to discriminate between its own or a conspecific's egg sac, and the ability to discriminate between an egg sac that had just been removed and an egg sac that was removed seven days earlier. When given a choice, females significantly chose their own egg sac over plastic beads of equal mass, preferred large plastic beads equal in mass to an egg sac over small plastic beads, round over faceted beads, and showed a non-significant tendency to attach black rather than white beads of equal mass. When given a choice between two conspecific egg sacs, spiders more often rejected those that had been removed from the mother seven days earlier than those that had been freshly removed. Spiders were unable to recognize their own egg sacs versus a conspecific's. Although spiders recognize egg sacs from non-egg sacs based on mass, texture, and presumably odor when given the choice, acceptance of non-egg sacs was common when no real egg sac was available. Also, females would not reattach their own egg sac once an artificial one had been attached. Attachment of any object on the spinnerets apparently ceases searching or attachment behavior.