Can pigs see in the dark?

This morning while riding the fences as I do every morning to ensure everyone is where they are supposed to be I believe I found out the answer to this question.  NO.  I drove up to the pig fence to make sure nothing ran through it at night and while most days the pigs are sleeping, today they were out and about.  I guess they thought I had corn for them (why I am not sure as they are in the middle of the sweet corn with plenty to eat) and one curious pig decided to keep walking right through the fence.  When he got out, so did the other 18.  Well, 18 loose pigs at 5:30 am is fun.  Luckily, they stayed close to the corn and I got some feed to coax them back.  If they wanted fed, they succeeded.  After counting about 7 times, I determined they were all there and put the fence back.  From now on I will walk to check their fence and keep an extra bag of corn in the vehicle.  Emergency rations!  We are lucky to be able to work with them so often as they are not at all wild and came back in when called.  At any rate, Good Morning All!