Close the opening of the bath toy
Children like to play with small rubber ducks or other toys in the bathtub, with a hot melt adhesive you should glue the lower opening better.
Many do not think so, but this bath toy can start to go moldy inside. Of course you dry the rubber animals after bathing, but they never really get dry inside, so mild mold develops. You can prevent this by simply closing the hole with a hot glue gun, so that no more water can penetrate and no more bacteria and mold can form inside.
