Dogs in conversation

I regret not taking video of these 2 dogs barking at each other, one bark in turn. They only did it once or twice.

Momotaro never barked at intruders until the more vocal Yuhi arrived 3 years later.

Facing each other:

Y: Yap!
M: Yap!
Y: Yap!
M: Yap!
Y: Yap Yap!
M: Yap!

I didn’t know why they were barking at each other. I imagine Yuhi wanted Momotaro to cooperate in some activity.