孤
=
孑
+
瓜
:
Gitta Giraffe (gu) is currently the space station's lone (孤) inhabitant. To feel less lonely (孤), she drew a mosquito's (孑) face on a melon (瓜) to have somebody to talk to in front of the space station (Ø1).
独
=
犭
+
虫
:
Everyone has left the space station, only the animals are left: Doggy Dog (du), the dachshund (犭) and the mosquito (虫). They have noone who throws them a stick or exposes their bare body parts to bite. All alone (独), they wait in the space station's entrance (Ø2).