Chickens refuse to eat or drink after fox attack

[lv99oddish]

A fox got 2 out of our 4 bird flock (everyone is 8 weeks old) a couple days ago while we turned out back for a few minutes. I thought if I was outside with them while working in the yard it would deter the fox that's been staking out our house for the past few weeks but it unfortunately did not. The fox terrorized the flock and killed 2 before we noticed and chased him off. Since then the 2 left have refused to eat or drink unless we put the food or water right in front of their beaks and all they do is huddle together on their perch. Are they in shock still? Like chicken ptsd? I go out a few times a day to hand feed them and hold them while they drink. I also leave the heat lamp on for them all night so they can be extra warm but they still just huddle and shove their faces into the corner of the coop.

Will adopting more chickens make them feel safer? What can I do?

 

[Wyorp Rock]

What's your coop/run set up like? Photos?

Likely they feel safest inside their coop. You don't mention your location or actually how warm it is outside, so a heat lamp may be overkill for 8wk old chicks.

Place their food/water inside their coop where they can reach it. They will eventually come down and eat, usually chickens will not starve themselves.
The loss of the other 2 disrupted their flock and pecking order.
Whenever I've had a predator issue, my birds are unsettled for several days, so just give them time.

Edited to add. And no, adopting more chickens won't make them feel safer. It might create a little drama though, you never know.