Straw or Fleece

my mum keeps saying they need straw in there carrier to sleep in but they dont use it they just kick it out and they prefere fleeces anyway what to do

By carrier do you mean what you take them in to the vets? If so they're not going to go to sleep anyway. Try using fleece, with hay on. It's less likely to be kicked out because they might eat it and your mum will probably agree to it more readily.