Is it normal for volunteers to come build a ramp and then two of your kittens mysteriously disappear?

Listen here Russ clearly you don't know how our kittens are and they wouldn't roam around they stay in the front were the workers were working

They live here and they were only in the front area and they know not to go past the front area, also as they were leaving we tried to tell them to stop because we couldn't find them

I'll bet the ramp is beautiful. If the kittens were roaming free..I would imagine they found another home.