i say your dad is thinkign he knows best (like my dad) but no one knows the materal love of a woman, other than a girl lol. just keep the littel guy in a shoebox with toilet paper, feed him bread soaked with milk, make sure he stays warm, has air flow (no tight lids). he doens't look like he'll go far, so dont' worry, i'm sure you can handle it. my dad used to tell me the same things. it boild down to the "if you love it, then leave it" rule, which does apply, if this werent a tiny baby with no hope. adult mouse, vole, toad or frog i agree, but this is tiny and helpless and hungry, adn you can help it, so go for it!! just say "hey dad, i'll keep him a while to feed him, you can always let him go later.
"If you can't change your fate, change your attitude." - Amy Tan