Keeping them warm

So it's their first night in the kennel tonight and im worried they will be cold!! they have a big litter tray, but it feels very 'open' if that makes sence! theres not little space for them to snuggle down etc

I have 1 heat pod which I am going to put in but not sure where to put it, because it will get covered in pee if it goes in their 'bed'/litter tray, hmmm...

I usually put the heat pad by their food bowl as Lola likes to sit on it while eating :lol: Or by a water bowl? Maybe in a corner? Or where they seem to congregate