The kids didn't deliberately play with food but sometimes there'll be some spots. What was worse was wall paint peeling off over time.

But yes, crumbs do fall through between mats and every now and then, got to thorough vacuum underneath. If liquid spills, it needs to get wiped and cleaned underneath too.

Also I will get the solid mats (not those with the alphabets or shapes, etc.), lesser cracks for crumbs to fall through.