Strange behavior while eating.

[castor]

Hello guys, i just osberved for the first time this:
I put a roach in the enclosure, he goes close to the tarentula, she "rush" close to him. Front legs 1cm. Then the roach didn't move for a while, neither the tarentula. Waited about 5 minutes. The roach was in between a water contain and window of the enclosure, not stuck but cornered.
Then the tarentula scan slowly the floor, put the 2 front legs on the roach, he still didn't move, she slowly goes with her perdipalpes, roach still feigned death. The tarentula keep slowly approaching the roach while touching (maybe pressure him down). Then she grab the wing of the roach, and put it in her teeths (cheliceras for the scientists) The scene was strangly slow, often she jumps so fast that i can't see any details, she just rush the food.
I'm not sure of it but as i seen it, it looks like she put some pressure him with her wholes legs, force him to stay still.
The tarentula is an adult B. Smithi. The Roach was adult too

Have you guys ever assist that kind of behavior ?
I promess, next time i see this could happening, i will film it ^^

 

[Nunua]

My A. geniculata juvenile often does this with dubia roaches. She does detect the feeder when it falls into the enclosure but as dubias tend to stand still when under stress and there is nowhere to hide, tarantula kinda loses the track of the roach even when having their legs on it. It's probably because tarantulas have bad eyesight, so when they hunt they rely on the vibrations / signals obtained via sensitive setae (longer hairs you can see all over the T) - When the prey stays still, tarantula does not sense it as well.

 

[WolfSpider]

I have also found that T’s lose interest quickly in prey if they are going into pre-molt.
I have a 6 inch P. cancerides that pounces on roaches and crickets and then ignores them. She has been doing it for 5 months. She also has a dark urt patch and rarely eats.