I am a wizard with an owl familiar (created by find familiar) that I wish to send on a long-distance delivery mission, requiring it to be away from me for several days. I would like to be able to check up on my familiar to make sure it hasn't been attacked or otherwise prevented from making its delivery. I'm hoping I can do this using the sending spell, but I'm unsure of exactly how the spell would work when communicating with a creature that doesn't speak a language. I'm confident that my familiar would receive my message, since the spell states:
The spell enables creatures with Intelligence scores of at least 1 to understand the meaning of your message.
However, it's not clear whether my familiar can respond, and if so, how. The spell says:
You send a short message of twenty-five words or less to a creature with which you are familiar. The creature hears the message in its mind, recognizes you as the sender if it knows you, and can answer in a like manner immediately.
So, the spell says that my familiar can "answer in a like manner", i.e. in "a short message of 25 words or less". However, my familiar (an owl) doesn't speak any languages, and it's not clear to me whether it's possible to make such a reply without a language. On the other hand, if a creature can understand my message without needing to understand a language, it seems logical that it could also reply. So, RAW, is my familiar capable of replying to my sending spell? If so, what form does that reply take? If not, can I still tell whether my message was received (i.e. can I tell whether my familiar is still alive to receive the message)?