Are you going to try it the way delisha described and let us know the results.Thanks pigeonguy- yes, I was being humorous. But also, no color on the eggs. Now I know that the poo and egg exit the same opening. But considering that chickens will poo every 7 minutes (read that somewhere), and lay an egg >1x per 24 hours, it only stands to reason that the intestinal opening would be more accessible. The egg, when being laid, closes off the poo opening. They just both exit the same vent hole is all.
Anyhoo...to be more graphic.
4 LF hens.
DH holds hen upside down. Me, wearing rubber gloves, has bottle of said color ready. We move to the door, to have better light. Now, while hen is being held upside down, I sort through feathers to access vent. Check vent for issues. Hen is opening and closing her vent during the process, as she doesn't know what's going on. I, like you, assumed ..(drop liquid in vent, end of story). So, I hold tiny plastic bottle up over her vent and drop in 3 or 4 large drops of food color. Hen opens and closes vent, because liquid is cold..apparently.
Toss hen back in coop, grab another, repeat procedure.
Wait for eggs to be laid...2 the next day...2 the day after. None have color streak.
1} Now, maybe I didn't put enough in (?)
2} Maybe, being chickens poo all the time, it did go in the wrong one.
3} I don't know.
BTW, we haven't culled any hens yet, so I have n hands on verification of vent opening on a non combative hen.
ps;![]()
Hence, that is why I am asking in here. It is all a learning process for me. I am new to chickens.