We have heard in lecture about the significance that titles (as well as other key markers) have in works of fiction. For Thank Your Mother for the Rabbits we discussed three allusions, One is to Mills' father: the phrase is one of the British music hall tag line he would characteristically repeat. Another is (as should be obvious) to his mother, who dominates the book -- as, we may conclude, she dominated Mills' psyche.
The third and most complex is the rabbit. This allusion involves what Mills calls "Symbols at your door" -- an element of your life which resonates powerfully, repeatedly and with meaning to you alone, (see pp 240-1.) In Mills life, a place from childhood -- a garden near Yately in southern England where he went away with, importantly, his mother & father individually -- and a particular rabbit-hutch remained with him as pure reality. (p 224.) The rabbit recurrs, flayed alive, in a scene from an American work of fiction; it blends into a crucified lamb in a drawing he made as boy; into a character of a German soldier spitted and impaled in a novel he wrote; and ultimately into a symbol of ... well, of an unbearably personal recounting of an excruciating family loss.
Note that, as a literary scholar, when you analyse the meaning of the title in a work of fiction, don't fail to look directly to the obvious. Both "mother" and "rabbits" are in the words of Mills' title, and, although the greatest titular significance is not always directly verbal, it not infrequently, as here, is.