Everyone who sent in solutions from Moorfield Junior School, Stockport agreed that:
There must be two spiders and one fly to make $22$ legs creeping across the web.
It is interesting to see the different ways of working this out:
Adam and Abigail$2$ spiders = $16$ legs ($2 \times 8 =16$)
Christopher and RichardWe doubled $8$ which made $16$, and we thought about the difference between $16$ and $22$ and the answer was $6$, so we added on a fly.
James and Luke
Adam and Anthony$2 \times 8 =16 = 2$ Spiders